Jack O Lantern Chocolate Pumpkin Mousse Cake

When your zombie guests arrive, they would be thrilled to see these mysterious glowing, smoking, or blood oozing chocolate Jack O Lanterns. Little do they know that when they bite into it, the luscious pumpkin mousse cake inside combined with the milk chocolate would elevate them from the underworld onto a heavenly cloud of bliss.

Made from scratch, these chocolate pumpkins are not only super delicious, they are quite magical and playful when it comes to presentations.

Step 1: Make the Milk Chocolate Jack O Lanterns

Ingredients and tools (for 6 pumpkin shells):

20 oz (600 grams) milk chocolate
(6) 4” to 5” diameter balloons
2 to 3 oz of white chocolate for painting the features
Plastic wrap
Silicon or rubber spatula
Pots and bowls for melting chocolate

Set a bowl on top of a pot of boiling water, and slowly melt the chocolate. Now you can skip to the dipping balloon part. But if you want a stronger and better looking shiny shell, read the following about how to “temper” chocolate like a pro.

When you take a bar of chocolate out of its package it is shiny and crisp. This is because it has been tempered, a technique used to stabilize the crystals in the chocolate. When the chocolate is simply melted then cooled, it will have lost its shine and snap. To regain those characteristics after melting you need to re-temper the chocolate. In addition the chocolate being shiny and crisp, there are other benefits to tempering. It will harden quickly at room temperature and stay that way almost indefinitely in the right conditions. Tempered chocolate also slightly contracts when it cools so it will release from the balloon easier.

There are a few techniques used to temper chocolate. They all call for melting the chocolate, cooling it, and then warming it slightly. All you need is a thermometer and patience. We used one of the easiest methods called seeding. The temperatures we give are for milk chocolate. They differ for dark and white chocolate.

The first step of seeding is to chop the chocolate finely and set 1/3 to the side. Put the remaining 2/3 in a stainless steel or glass bowl and place over a pot of steaming water to create a double boiler. Stir the chocolate occasionally until it is melted and has reached 105-110°F. Remove the chocolate from the heat, wiping the bottom of the bowl dry, and being careful not to get any water in the chocolate.
In 3 parts, add the reserved chocolate, stirring until melted after each addition. The goal is to bring the chocolate down to 81°F. If the chocolate is still not cool enough after the last addition, allow the chocolate to sit, stirring occasionally, until cool. Now carefully return the bowl of chocolate to the double boiler for 20 seconds at a time, stirring constantly, until the temperature rises to 86° to 88°F (30º-31ºC). This step can happen very quickly so be careful not to hold the chocolate over the steam too long!

Now your chocolate should be tempered. To test it spread a small amount onto a piece of parchment. Within 5 minutes the chocolate should harden and be streak free. If you don’t think the chocolate is tempered, repeat the process.
If you don’t want to go through the trouble of tempering you can just use chocolate that has been melted but you will want to let the dipped chocolates sit in the refrigerator overnight before attempting to pull out the plastic wrapped balloon. You also don’t want to keep the chocolate pumpkin out of the refrigerator for long periods of time until serving or the chocolate will start to soften and may lose its form.

Now it’s dipping time. Blow the balloons to 4” -5” diameter. Wrap each balloon in plastic wrap and gather at the top. The plastic wrap serves 3 functions- it's food safe, it forms cool ridges and add nice details to our pumpkins, and it helps to carry the weight of the chocolate since balloons can stretch.

Hold the gathering tip and dip the balloons in the melted / tempered chocolate, also use the spatula to paint the chocolate as you get closer to the top. Leave a 2” to 3” opening at the top. Set the shells on parchment paper lined plate or sheet pan to cool. Put them in the fridge for 1-2 hours to make them extra hard before punching the balloon and carefully peeling away the plastic wrap.

To carve out the eyes, heat a small knife over a candle flame for a few seconds, take a deep breath, and go for it! It's a good idea to wear rubber gloves so we don't leave finger prints on our shiny pretty chocolate. Then melt the white chocolate, put them in a small paper cone like those cone cups or make one with parchment paper, cut a tiny hole at the tip, and pipe the mouth, teeth, highlight around the eyes, and any features that you fancy!

These shells can be made days ahead, wrapped and stored in the fridge. If they are tempered, they can be stored at cool room temperature.

A couple of good tips:

Keep the shells at a distance from the heat of oven and stove as you proceed to make the cake and mousse, or they will start melting
Wait for the melted/tempered chocolate to cool a little to a warm to the touch state to start dipping, otherwise the balloons may burst and (especially if you use balloon only with no wrap) you will have chocolate splattered faces and walls - guess how we know that? =)

Step 2: Make Pumpkin Sponge Cake

Ingredients (makes two 8" cakes)

1 3/4 cup all purpose flour
1 teaspoon cinnamon
1 teaspoon baking soda
5 medium or 4 large eggs
2 cups (1lb) granulated sugar
13 oz pumpkin puree

Sift together the flour, cinnamon, and baking soda.
Whip eggs and sugar until light and thick.
Add the pumpkin puree and mix in low speed until incorporated.
Gently fold in the dry sifted ingredients.
Divide the batter in two 8" cake pans that are lined with paper and greased.
Bake at 350° F for 20-25 minutes. Let cool for 10 minutes, take them out of the pan.

Note: the Trader Joe's pumpkin puree we used is more watery than other brands, so the cake took 10 minutes longer. Use a skewer to test, if it come out clean, the cake is done.

Step 3: Make Pumpkin Mousse

Ingredients (enough to fill 6 shells) :

9 oz milk
3 egg yolk
3 oz granulated sugar
1/4 cup cornstarch
18 oz pumpkin puree
12 oz heavy cream whipped to stiff peaks ( or whipping cream)
1/4 tsp cinnamon
pinch of nutmeg
pinch of clove
1/2 oz powder gelatin
1/4 cup cold water

Bloom(aka dissolve) the gelatin in cold water and set aside.
Warm the milk and the spices.
When the milk is warm, stir in ½ of the sugar and the pumpkin.
Mix the remaining sugar with the cornstarch.
Stir the egg yolks into the cornstarch and sugar.
When the milk-pumpkin mixture boils, whisk a small amount into the egg yolks just to dilute them without scrambling, then add the diluted egg yolk back into the pot, stirring constantly over very low heat with the whisk, until thick, about 2-3 minutes.
Stir in the hydrated gelatin.
Place on a sheet pan, cover with plastic wrap and allow to cool to room temperature.

When the pumpkin custard is cool, gently fold in the whipped cream. Hold off on this step until you are ready to assemble the cake and pipe the mousse(see next step), because it's easier while at a softer consistency. The mousse will set more to a firmer state once piped and chilled.

Step 4: Assemble Pumpkin Mousse Cake

Slice the cake through the middle into half the thickness. Cut the cake into discs which fit inside the chocolate pumpkins. As you go up the discs get bigger.

Use a pastry bag to pipe a layer of mousse on the bottom. Then put a disc of cake. Repeat these 2 layers one more time. make sure the top layer stops just below the eyes.

Use the extra cake and mousse to make a delicious pumpkin trifle and treat yourself even though you haven't done any tricks yet!

Next we start creating some magical effects!

Step 5: Glowing Jack O Lantern

Light a birthday candle in the center of the cake, and you have a glowing pumpkin. How easy is that? If you want to give your Halloween dinner a cozy ending, this is the way to go.

Step 6: Smoking Jack O Lantern

We had so much fun with this one! We took some photos outside the pumpkin so you can see more clearly how it was done.

Be very careful when working with dry ice!! Please take a good look at this page of dry ice safety info - http://www.dryiceinfo.com/safe.htm

Right before serving, carefully break some dry ice into small pieces. Fill the 2" shot glass with 1/3 water. Place it inside the pumpkin. Use needle nose pliers to pick up a small piece of dry ice, size of a thumbnail is enough, and place it inside the shot glass. Enjoy the ghostly smoke rising!

Step 7: Blood Oozing Jack O Lantern

I really should make my hubby write this part because I want to pass out at the sight of blood!

OK here's how we did it- put a tea light candle into a 2" shot glass, so the heat of the flame can warm the top half of the glass. Mix red food color into your vanilla ice cream, scoop out a little cake and mousse at center, sink the shot glass halfway so the heat from candle flame can melt the ice cream that you spoon around it. The melted ice cream becomes a delicious sauce although it looks spooky.

You may take your time watching the blood flowing out, but I need to cover my eyes and move on to the next step: enjoy my Jack O Lantern with WHITE vanilla ice cream! Happy Halloween!