In my family, Christmas dinner is always the main focus of the holiday season. Once a year, we congregate from the far corners of the globe to sit around a table in my parents' house, stuff ourselves silly, drink some wine and try not to argue about anything too personal. It's kind of a big deal.

Naturally, there's a lot of food. The oversized turkey. The painstakingly prepared roast potatoes. The sausages wrapped in bacon, the spiced cabbage, the Brussels sprouts, the assorted vegetables, the multiple sauces. The works.

None of this would get cooked without my mother, who takes it upon herself every year to spend weeks planning and days preparing the perfect Christmas dinner. The rest of us are deputised to various tasks around the kitchen, but the bulk of the cooking work always falls to my mother. We are all hugely grateful to her and, I like to think, try to help out as much as we can. For the past couple of years, to give her one less thing to worry about, I've persuaded her to let me take sole responsibility for the dessert.

Christmas dessert is a tricky thing. Everybody's already stuffed after the main course and, deep down, nobody really likes Christmas pudding. What's needed is something fresh, something exciting, something that will grab people's attention. What's needed is combination of rich chocolate cake, delicious ice cream and seasonal sorbet all smothered in meringue, drizzled in rum and set alight with a carefully controlled remote detonation that singes the eyebrows off anyone leaning in too close.

What's needed is Nuked Alaska.

Nuked Alaska is a variation of baked Alaska, a dish in which a block of ice cream is baked into a crust of meringue without melting, resulting in a dessert which is hot, cold and delicious.

This recipe owes a lot to Heston Blumenthal, from whom I took the idea and method for preparing a concentric sorbet and ice cream core. The chocolate (and Guinness) sponge recipe comes from Nigella Lawson, by way of Gizzi Erskine. Their original recipes are all available online.

This is fairly time-consuming recipe, parts of which require preparation at least 36 hours before serving (to allow the ice cream and sorbet to freeze) and parts of which require preparation at the very last minute. This recipe does not require an ice cream machine. It does, however, require some slightly specialist materials for the pyrotechnic effects. I'm going to assume that they're all legal where you live, but please don't count on that being the case.

The quantities of food used in the recipe are also somewhat wasteful. Well, wasteful in the sense that you'll be left with several spare servings of delicious sorbet, chocolate cake and meringue that can be eaten on their own at your convenience. I cooked this without knowing how much of each ingredient would be required, but aware that the leftovers would all be used and appreciated.

Step 1: A Brief Discussion and a Schematic

The backbone of this dessert will be a block of ice cream. The spinal cord within that backbone will be a tube of sorbet. Both of these things will be very cold.

If you put a block of ice cream into a hot oven, you'd expect it to melt. Unfortunately, liquid ice cream lacks a certain flair when presented as a dessert, so you'll need a way to keep the ice cream solid.

Fortunately, meringue, being a foam full of air bubbles, is a great thermal insulator. By coating a block of ice cream in a Thermos-like layer of meringue, you can prevent it from even noticing the fierce blaze of your oven for several minutes. If you make sure the ice cream is rock hard before it goes into the oven, it will be another few minutes before it starts to break a sweat. That's all the time you need to cook a soft meringue.

To help insulate the ice cream even further, you're going to include a pre-cooked layer of crisp chocolate meringue. This has the bonus of providing some crunchiness to the dessert, even if you undercook the outer layer of meringue.

Rather than try to cook a layer of meringue underneath your block of ice cream, you're going to insulate the base with a thick layer of rich chocolate sponge. This sponge will also hold a thin layer of caramel which will liquify as the dessert is cooked.

Before you get started, have a look at the diagram below to get a feel for what you'll be making.

Step 2: Ingredients, Appliances, Tools and Materials

I'll list all of the edible ingredients twice: first organised by how they'll be used and then again as a list of total quantities you'll need. That way, if you want to change or replace one of the components of the dessert (e.g. use a different ice cream recipe), you can easily figure out which quantities you need to change.

Ingredients by dessert component

Blackberry and cranberry sorbet:

2 egg whites
250g caster sugar
200ml water
450g blackberries
300g cranberries

Banana Crunchie ice cream:

4 egg whites
1/2 tsp table salt
350g caster sugar
180ml water
600ml double cream
5 bananas, turning brown
6 x 40g Cadbury's Crunchie bars

White chocolate tube:

150g white cooking chocolate

Caramel:

150g ready-made caramel (or condensed milk, which can be made into caramel)

Chocolate Guinness cake:

250ml Guinness beer
250g unsalted butter
150g dark/plain chocolate (70% cocoa solids or more)
50g cocoa powder
2 eggs
400g caster sugar
150ml plain yoghurt
275g plain flour
3 tsp bicarbonate of soda

Hard chocolate Italian meringue:

3 egg whites
1/2 tsp table salt
250g caster sugar
125ml water
75g dark/plain chocolate (70% cocoa solids or more)

Soft Italian meringue coating:

6 egg whites
1 tsp table salt
500g caster sugar
250ml water
1/2 tsp tartaric acid

Rum:

150ml rum

All of the ingredients you'll need

17 eggs
1.75kg caster sugar
755ml water
450g blackberries
300g cranberries
2 tsp table salt
600ml double cream
5 bananas, turning brown
6 x 40g Cadbury's Crunchie bars
150g white cooking chocolate
150g ready-made caramel (or condensed milk, which can be made into caramel)
250ml Guinness beer
250g unsalted butter
225g dark/plain chocolate (70% cocoa solids or more)
50g cocoa powder
150ml plain yoghurt
275g plain flour
3 tsp bicarbonate of soda
1/2 tsp tartaric acid
150ml rum

Don't even try to calculate the calorific content of this dessert. If you do, you really won't want to cook it.

Other things you'll need for cooking

Assorted mixing bowls, saucepans, baking trays, etc.
2 disposable aluminium foil trays, smaller than a baking tray but with bases larger than 30cm x 15cm.
Sieve
Greaseproof paper
Cling film
A4 sheet of plastic/acetate (e.g. plastic document cover)
Cardboard (43cm by 28cm)
Craft knife
Adhesive tape
Grater
Piping bag

Electric whisk
Blender
Freezer
Oven
Blowtorch

For the detonator and pyrotechnics (not strictly necessary, but fun)

8 sheets of flash paper (~20cm square)
Constantan resistance wire / nichrome wire (~10cm)
Insulated electrical wire (~2.5m)
Push button
2 x 9V batteries
2 battery connectors
Insulation tape
Solder
Soldering iron
Thin cardboard tube, e.g. tube from inside roll of cling film

Step 3: The Sorbet

Mmm... seasonal fruits in seasonal snow...

Ingredients

2 egg whites
250g caster sugar
200ml water
450g blackberries
300g cranberries

Rinse the blackberries and cranberries in a sieve, then blend them.

Strain the blended fruit through a sieve into a bowl. The pulp will be full of seeds and fibre, so you'll need to encourage as much liquid through the sieve as you can by pressing down and scraping with a spoon. Don't worry that the mixture tastes terrible; cranberries have something of an acquired taste before they've been sweetened.

Dissolve the sugar in the water over a low heat, then turn up the heat and boil for about three minutes. Turn off the heat, stir in the strained fruit purée and allow to cool. Once cool, transfer the mixture into a shallow baking tray and freeze until it turns slushy. This can take up to 4 hours, depending on your freezer.

Scoop the fruity slush into a bowl and beat it until it's soft again. Whisk the egg whites to soft peaks, then fold them into the chilled purée. Spoon the mixture back into the baking tray and freeze overnight or until firm.

Step 4: The White Chocolate Tube

The sorbet will be contained in a hollow white chocolate cylinder which will be suspended in the centre of the ice cream (which will, in turn, be encased in two layers of meringue).

Ingredients

150g white cooking chocolate

Make a mould for your chocolate by rolling up a sheet of flexible plastic into a cylinder 4cm in diameter and at least 27cm in length. Tape the free edge of the cylinder to hold it together and cover one end with cling film and tape so that it doesn't leak.

Melt the white chocolate in a bowl over hot water, then pour it into the mould. Rotate the chocolate-filled mould in your hands for several minutes so that all of the surfaces are covered, then place it upright in a refrigerator or a freezer to set. It should be fully solid in a matter of minutes.

Once you're sure the chocolate is absolutely rigid, carefully cut the tape off the mould with a craft knife and peel the mould away to reveal a beautiful chocolate tube.

Step 5: The Ice Cream Mould

The ice cream mould will be a simple cardboard box with an open top. The base should measure 25cm by 10cm and the sides should be 9cm tall.

Cut out a simple net with a craft knife and stick it together with tape. Place a sheet of cling film across the open top of the box and push the cling film into all of the corners so that the box is now lined with one continuous piece of film. Tape the cling film in place.

You now have a partially biodegradable coffin in which to inter your ice cream within your freezer.

Step 6: Filling the Chocolate Tube

Remove the sorbet from the freezer. If it is very hard, leave it for ten minutes or so to let it soften slightly.

Using a warm knife, trim the chilled chocolate cylinder so that it fits into the cardboard mould.

Scoop sorbet into the piping bag and pipe it into the chilled chocolate cylinder until the cylinder is completely full.

Leave the filled cylinder upright in the freezer until you need it during the next step.

Step 7: The Ice Cream

The bulk of this dessert will be made of ice cream, so you had better choose a good one. I opted for a reliable parfait-like recipe flavoured with bananas and Crunchie bars. The soft caramelly flavour of the Crunchies balances out the strongly aromatic bananas nicely, while the smoothness of the ice cream contrasts pleasantly with the Crunchie bars', well, crunchiness*.

Ingredients

4 egg whites
1/2 tsp table salt
350g caster sugar
180ml water
600ml double cream
5 bananas, turning brown
6 x 40g Cadbury's Crunchie bars

This ice cream recipe is based around a simple Italian meringue. This makes for a fluffy ice cream mixture which has the great advantage of not requiring any churning while it sets. No ice cream machine is required; you can just make the mixture and stick it in the freezer to set overnight.

Make sure your bananas are at least partially, if not fully, brown to really get the good flavours out of them. Any even slightly green banana will be detectable as an odd, astringent note in the final ice cream

The Italian meringue recipe will be used twice more in making this dessert, so I've made a point of marking it out separately below.

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How to make Italian meringue

Whereas Swiss meringue is made by beating sugar into whisked egg whites and then cooking, Italian meringue is made using a hot sugar syrup which partially cooks the egg whites as you combine them. This makes for a firmer, more workable meringue which holds its shape better and, usefully, can be left in the bowl for an hour or two without losing its foaminess.

To make the sugar syrup dissolve the sugar in the water over a low heat, then turn the heat up to start the solution simmering.

In an immaculately rinsed bowl (any trace of soap, detergent or oil will destroy your meringues), beat the egg whites with the salt until you have a stiff, glossy mixture. Once the sugar syrup has been simmering for about four minutes, pour it slowly into the egg whites in a thin, steady stream while you beat the egg whites with an electric whisk. This ensures that the hot sugar is spread as evenly as possible throughout the egg whites, cooking it evenly while incorporating more air.

Continue to beat the meringue until it is thick and glossy.

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Peel the bananas and blend with a few tablespoons of the double cream until you have a smooth mixture. Add four of the Crunchie bars to the blender and blend again. These Crunchie bars are more for flavour than texture, so get them as finely ground as possible.

Fold the banana/Crunchie/cream mixture into the meringue.

Whip the rest of the double cream in a separate bowl until it is thick but not so much that it turns buttery. Fold the cream into the meringue to complete your ice cream mixture.

Pour or scoop the mixture into your plastic-lined cardboard mould until the mould is half full. Carefully place your chocolate cylinder full of sorbet onto this bed of ice cream, then fill the rest of the mould with ice cream.

You should now have a neatly packed little ice creamy coffin in which to inter your sorbet cylinder within the depths of your freezer. Put the whole mould back into the freezer overnight for the ice cream to set.

* If you're in the mood for being a bit pretentious and food critic-y, take a moment to consider how this contrast is a microcosm of the finished dessert's assorted contrasts of texture, flavour and, most importantly for a baked Alaska, temperature. These playful contrasts are what make baked Alaska such an interesting dish to eat as well as to prepare. Ideally, the diners should be momentarily tickled by the sudden changes on their palates of hot meringue to cold ice cream, sweet caramel to tart sorbet, moist cake to crisp biscuity meringue and so on. Another hat tip to Heston Blumenthal is warranted here, I think.

Step 8: The Chocolate Guinness Cake

This recipe is for a thick and moist chocolate cake to provide the insulation for the base of your dessert. The Guinness adds an extra element of malty richness, but is not tastable as beer in the finished dessert. The quantities below will fill a large (30cm x 45cm) brownie tray with cake, but the finished dessert will only require a 25cm x 10cm slice of this. I'm afraid that you'll be left over with a lot of cake. I can only hope that you'll find a way to manage this regrettable surplus.

Ingredients

250ml Guinness beer
250g unsalted butter
150g dark/plain chocolate (70% cocoa solids or more)
50g cocoa powder
2 eggs
400g caster sugar
150ml plain yoghurt
275g plain flour
3 tsp bicarbonate of soda

Line a large baking tray with baking paper and preheat the oven to 180°C.

Melt the chocolate in a heatproof bowl over boiling water.

Chop the butter and heat it with the Guinness in a large pan until melted, then remove from the heat and stir in the sugar, cocoa powder and molten chocolate.

In a separate bowl, beat the eggs into the yoghurt, then add this to the pan of chocolatey goodness. Now whisk in the flour and the bicarbonate of soda, being sure to whisk away lumps.

Pour the mixture into the lined baking tray and bake in the oven for at least 45 minutes. To check whether the cake is cooked, poke a knife into its centre. If the blade comes out clean and dry rather than wet and gooey, it's finished.

Remove the cake from the oven and allow it too cool for a few hours to firm up. It will naturally sink when you remove it from the oven. Don't be alarmed; that's perfectly normal.

Step 9: The Hard Chocolate Meringue

Now you're going to make the two rectangles of crisp Italian meringue which will form the inner layer of the dessert's meringue shell.

Ingredients

3 egg whites
1/2 tsp table salt
250g caster sugar
125ml water
75g dark/plain chocolate (70% cocoa solids or more)

Make an Italian meringue, just as you did before in Step 7.

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How to make Italian meringue

To make the sugar syrup dissolve the sugar in the water over a low heat, then turn the heat up to start the solution simmering.

In an immaculately rinsed bowl (any trace of soap, detergent or oil will destroy your meringues), beat the egg whites with the salt until you have a stiff, glossy mixture. Once the sugar syrup has been simmering for about four minutes, pour it slowly into the egg whites in a thin, steady stream while you beat the egg whites with an electric whisk. This ensures that the hot sugar is spread as evenly as possible throughout the egg whites, cooking it evenly while incorporating more air.

Continue to beat the meringue until it is thick and glossy.

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Heat an oven to 110°C and line a baking tray with baking paper.

Grate the chocolate into large shavings, then fold it carefully into the meringue. Do not over-stir or whisk the meringue at this stage, as the fat in the chocolate will reduce the surface tension of the air bubbles and turn the firm foam into a runny cream.

Using a piping bag, pipe out two rectangles of the chocolate meringue onto the lined tray. Each rectangle should measure about 25cm x 10cm.

Bake the meringue rectangles in the oven for 2.5 hours, then remove to cool. Once they are cool, carefully removed them from the tray. Don't worry if you crack them slightly.

Step 10: The Detonator

You've done a lot of cooking over the past day or two, so it's time to take a break. I suggest you relax with some recreational electronic wiring.

Yes, this is a recipe that includes plans for building a pyrotechnic detonator. No, it's not absolutely vital. It does, however, add a fantastic element of drama to any dinner party. There's nothing better for waking up Granny during Christmas dinner than passing her a big red button on the end of a wire, running for cover behind the couch and shouting, "Go, go, GO!"

Safety warning: This is fun, but dangerous. It involves fire and electricity and entertaining combinations of the two. Please be sensible if you attempt this. Kids, get an adult to help you. Adults, you should know better than to be doing this. Adult kids, proceed with caution.

This is how baked Alaska is traditionally served:

Warm rum is poured over and around the finished dessert, then set alight with a match to provide a faint blue flame. Polite "oohs" and "aahs" are elicited from the diners.

This is how your Nuked Alaska will be served:

You will be holding a detonator button. Pushing the button will complete a circuit which will rapidly heat a short length of resistance wire. The hot resistance wire will ignite a match head. The flaming match head will ignite a ring of flash paper surrounding your dessert. This will create a momentarily blinding fireball which will disappear in a split-second to reveal a faint blue flame over a mountain of meringue. Astonished silence followed by hysterical laughter will be your reward.

Here's what you'll need make the detonator:

Constantan resistance wire / nichrome wire (~10cm)
Insulated electrical wire (~2.5m)
Push button
2 x 9V batteries
2 battery connectors
Insulation tape
Solder
Soldering iron
Thin cardboard tube, e.g. tube from inside roll of cling film

Solder the simple circuit shown below, leaving out the resistor (which will in fact be a length of resistance wire which you will attach later). It has two 9V batteries arranged in parallel to provide a current across a resistor, which is at the end of two one-metre-long insulated wires. The circuit is interrupted by a push-button switch. When the button is pressed, the circuit is completed and current will flow across the resistor.

Build the circuit into a convenient housing. A thin cardboard tube is ideal for this, as it can be gripped in one hand so that the button can be pressed by thumb. Seal the tube in insulation tape, leaving the two long wires trailing from one end.

Wind a 10cm length of resistance wire around a match head, leaving ~2cm free wire at each end. This is easiest to do by using a whole match, then snipping away the shaft of the match with pliers.

Connect the two long wires from the detonator to different ends of the resistance wire. You now have a potentially very dangerous electrical circuit. If you press the button, the match head will ignite.

DO NOT leave the circuit intact and unattended. Remove the batteries when you are not using it.

Note: This detonator can also be used for igniting fireworks. While it might look like a scary bit of terrorist kit, it is nothing fancier than a way of lighting a match from afar. Please do not use it to set fire to anything explosive or anything that does not wish to be set on fire.

Step 11: The Flash Paper Fireball

Flash paper is another name for thin sheets of highly flammable nitrocellulose. When it catches light, it burns incredibly rapidly and very brightly, leaving nothing more than a trace of ash. Magicians often use it to provide a quick distraction during an illusion or to spice up an otherwise dull sleight of hand.

You can buy flash paper from any reputable magic shop, if such a thing can be said to exist. If you live in London, I recommend Davenports Magic, an old family-run magic shop that has lurked in the basement of Charing Cross Station since 1898.

Flash paper is stored wet to avoid accidental combustion, so you'll have to dry out the required amount overnight before you use it for your Nuked Alaska.

How to arrange your flash paper for a fireball

You'll need:

8 sheets of flash paper (~20cm square)
1 baking tray
2 disposable aluminium foil trays, smaller than your baking tray but with bases larger than 30cm x 15cm.
Insulation tape

You don't want to have the flash paper touching your food and leaving chemical residue over the dessert, so it will instead be on a separate tray, surrounding the main dish.

Place one of the foil trays in the centre of the larger baking tray. Crumple seven of the sheets of flash paper so that they lie on the larger tray, surrounding the foil tray. Make sure that they are all touching, but twisting their ends together.

With the remaining piece of flash paper, make a thin strand that will lead from the larger tray to inside the baking tray. This will act as a fuse which will ignite the rum in the main central dish when the flash paper burns.

Note that you will cook the Nuked Alaska in another aluminium foil tray, which you will then place inside the one you have surrounded by flash paper. This is to minimise the risk of accidentally igniting the flash paper by bringing it directly into contact with a hot tray.

Tuck the match head wrapped in resistance wire underneath the flash paper at one end of the larger tray and tape the connecting wires in place. You should now have a tray rigged to detonate in an incredible, but brief (and hopefully relatively safe) fireball.

Step 12: Assembly on the Day

OK, let's get back to the cookery.

Every previous stage of this recipe can be completed days in advance of serving, but the rest will have to be carried out on the day, in that insulin-induced lull between the main course and dessert.

Ingredients

6 egg whites
1 tsp table salt
500g caster sugar
250ml water
1/2 tsp tartaric acid
150ml rum

Preheat the oven to 200°C.

Prepare an Italian meringue. You'll do this just as before, but with some tartaric acid added. This stabilises the egg whites when they foam. Don't use tartaric acid if you're using a copper bowl or eggs older than 10 days.

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How to make Italian meringue

To make the sugar syrup dissolve the sugar in the water over a low heat, then turn the heat up to start the solution simmering.

In an immaculately rinsed bowl (any trace of soap, detergent or oil will destroy your meringues), beat the egg whites with the salt and tartaric acid until you have a stiff, glossy mixture. Once the sugar syrup has been simmering for about four minutes, pour it slowly into the egg whites in a thin, steady stream while you beat the egg whites with an electric whisk. This ensures that the hot sugar is spread as evenly as possible throughout the egg whites, cooking it evenly while incorporating more air.

Continue to beat the meringue until it is thick and glossy.

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Remove the chocolate Guinness cake from its baking tray, if you haven't already, and trim it to 25cm x 10cm. If the top is uneven, use a knife to level it off. Place the trimmed cake in the centre of the unused aluminium foil tray.

With a knife and a spoon, dig a trench in the centre of the trimmed cake and fill it with a pool of caramel.

Remove the ice cream from the freezer and cut away the cardboard coffin to reveal a sturdy ice cream brick. Place this on top of the caramel-filled cake slice.

Press the two crispy chocolate meringue rectangles against the sides of the ice cream block, crumbling the meringue slightly as you push it up against the ice cream.

Using a piping bag, carefully pipe the fresh Italian meringue over the ice cream cake, making sure that it is entirely covered (including the hard meringue you have already stuck to the sides). Don't feel the need to use all of the meringue; just use enough for a consistent 1-2cm covering.

Step 13: Cooking on the Day

Steel yourself and put the entire dessert into the oven for five minutes. Cross your fingers if that makes you feel better.

Warm the rum gently in a small pan.

After five minutes, open the oven door and give the dessert a gentle poke with a spoon. If the meringue is still very soft and the ice cream still very firm, close the oven door and continue to cook the dessert for a few more minutes. Use your own judgement to determine when it is finished. Remember that the outer layer of meringue is already partially cooked and is delicious when warm and soft. It does not need to turn entirely hard.

Remove the dessert from the oven and brown it artistically with a blowtorch.

Pour some of the warmed rum over the top of the dessert and the rest around the dessert but in the same tray.

Carefully transfer the dessert tray into the tray you have already surrounded with flash paper, then make sure that one end of the flash paper is dipping into the rum around the dessert.

Step 14: Serving

Clear some space on the table and carefully place the large metal tray containing the flash paper, the two aluminium foil trays and the dessert in a place where everyone can see but nobody can touch.

Stand well back and ask for a countdown.

Detonate.