Far simpler than restaurants would like you to believe, a flourless chocolate cake is a real crowd-pleaser and proof positive that you are indeed the masterbaker (sic) we all know you to be.
Three simple ingredients, some standard kitchen tools and a bit of planning can net you one of these delicious cakes with a minimum of effort. Just do yourself a favor and keep in mind that it would be a patently bad idea to scarf the whole thing by yourself on a lonely Saturday night...
Note: Please keep in mind that a classic flourless chocolate cake is cake in name only, but this particular variant is exceptionally strict in its definition. It is as much 'cake' as can be made given the ingredients. If what you seek is the flashy equivalent of fluffy Jell-O Pudding baked in a ramekin you would do well to look elsewhere. Also, so-called "lava cakes" (which are simply over-buttered, under-done chocolate cakes in ramekins) do not fall within the purview of "flourless" for our definition.
With that in mind, let us continue towards the delicious confection that is the flourless chocolate cake.
Step 1: Tools
As promised all the tools used here should be well within the reach of an average kitchen, especially if you have ever baked anything before this:
- A whisk (or two)
- Stockpot, 4 qt. or larger (size is important only in relation to your bowl, as will be seen)
- Borosilicate (e.g. Pyrex) glass (or some other heat resistant material) bowls, I would recommend two. One needs to have a larger diameter than the top of your stockpot, the other only needs to be large enough to hold about two quarts.
- A large enough baking dish to allow a 9" round springform pan to sit reasonably flat on the bottom. This could be a "casserole" dish or a roasting pan or even the bottom half of a broiler tray. You will want to sides to be taller than an inch and a half.
- A kettle or saucepan in the one quart range in which to boil water
- Parchment Paper
- Aluminum Foil
And the one item that may or may not be in every kitchen:
- An 8" or 9" round springform pan
Nice to have is:
- A flexible spatula (or two)
- Oven mitt(s)
- An instant-read thermometer
- A stand mixer with a whisk attachment
- An oven thermometer
Step 2: Ingredients
An exceptionally simple list with some caveats:
- One pound of good quality semisweet or bittersweet chocolate. If you're buying chips instead of bars, be sure to get two bags as standard bags of chips are only twelve ounces. I have had good luck with Ghirardelli 60% cacao bittersweet baking chips. Chips have the advantage of melting quicker and more evenly than a chopped bar and makes less of a mess in the prep process.
- Two sticks of unsalted butter. Your choice on brand/type, but I would personally lean towards a higher butterfat content without straying totally into the realm of "European Butter"
- Eight eggs, large and straight from the fridge. Again, your choice on brand/type but I have a true and completely unfounded fondness for free range eggs in baked goods.
And that's it. Because of the low ingredient count, the quality of the included ingredients is of tantamount importance as I hope I have expressed already. The quality of the butter and eggs can be somewhat sacrificed for a good quality chocolate in regards to price, but it would be best to use the highest quality that can be afforded for all the ingredients.
(while a valid argument can be made that Ghirardelli is not exactly the best of all available chocolates, it is certainly sufficient for our purposes and the cake turns out nicely when it is used)
Note: Some people would see fit to include a small quantity of coffee liqueur (or orange, or rum, or, or, or...) but I personally don't see the need. If you do, feel free to add in two to four tablespoons of your tipple at the beginning of the melting process.
Step 3: Setup
We begin the process by preparing the necessary items.
First, the oven needs to be preheated to 325 degrees Fahrenheit. Normal caveats apply in that the temperature needs to be verified, as the majority of ovens do not accurately hold the temperature shown on the control knob. This may seem a bit nit-picky, but is in fact very important for this particular cake.
Next, put the kettle on. You will need your quart of water at a full boil when the cake is ready to go into the oven.
Fill your large pot with around a quart of water and begin to heat it. You do not want this to boil!
Prepare your springform pan by lining the bottom with a round piece of parchment paper. There is a photo below showing a method to cut a parchment round to fit the bottom of the pan. Grease the sides of the pan with butter and wrap the bottom half of the pan (on the outside) in at least two layers of aluminum foil.
Dice your butter and keep it cold. About twenty pieces out of the two sticks is small enough.
If you decided to ignore the forewarning and are using a bar of chocolate instead of chips, chop your bar into small pieces of relatively even size.
Step 4: And So It Begins
With your two containers (kettle and stockpot) of water boiling, springform pan prepped and oven preheating, take your eight cold eggs out of the refrigerator and break them into either your mixing bowl or the bowl of your stand mixer.
Begin to whisk the eggs. About five minutes from now, you should have a foamy volume of eggs about twice as large as when they started (about one quart). This is where a stand mixer comes in handy, unless of course you have a helper or you're an alternate hammer thrower for the 2012 Summer Olympics.
While the eggs are whisking or perhaps after, place your larger, heat-resistant bowl on top of your large stockpot of not boiling water. Place both the chocolate and the butter into the bowl. This arrangement is used as a double-boiler to prevent heat damage to the chocolate. If you have a legitimate double-boiler, by all means use it! Stir the mixture gently and very occasionally as it melts. Your target temperature is between 110 and 115 degrees Fahrenheit. Be sure to stir before taking the temperature and to keep the tip of the thermometer off the bottom of the bowl. Once the desired temperature is reached, remove the entire bowl from the pot, place it on a trivet or other heat resistant item and shut off the stove burner.
Step 5: Folding
I warn you now, I am going to beat this to death. This is easily the most important step to successfully making this cake and you need to read this before you begin to work on the cake.
The egg foam needs to be folded into the chocolate mixture, one third at a time, as gently as is possible. (Unfamiliar with folding? Search YouTube for "baking folding".)
Again, as gently as is possible.
Are you going to be gentle?
You should be.
The key to this entire cake coming together properly is the maintenance of the air bubbles in the egg foam. If you mistreat the foam, pour it all in at once and go at it with a hand mixer you will end up with a rather nasty batch of chocolate jerky treats. Think senile grandmother fudge with a light dusting of garden dirt.
So you will be gentle.
Gently add one third of the egg foam to the bowl containing the chocolate mixture. Gently fold the egg foam into the chocolate. When the foam is fully incorporated, gently add the next third and gently fold it in. Continue being gentle with the final third...
If you weren't gentle:
The gods of baking will smite you and make your cake taste like a delicate combination of coffee grounds and cat litter. You have been warned.
Step 6: Final Steps and Baking
With your fully assembled cake batter at the ready:
Scrape the batter into the springform pan. Make sure the top is reasonably flat so it doesn't look weird when it comes out of the oven.
Place the loaded springform gently into the baking dish/roaster/broiler tray. Pour your boiling water into the baking dish, not the springform. You want at least an inch of water in the dish. This is called a water bath (or bain-marie) and is commonly used in baking.
Place the entire assembly gently in the oven (I swear that's the last gently...) to bake.
Your baking time will depend on the diameter of the pan you used. An 8" pan will run about 24 minutes while a 9" will run about 20 minutes. Either way, the key it to remove the cake when the internal temperature is 140 degrees Fahrenheit.
Step 7: Post-bake Procedures and Warnings
When the cake has finished cooking and its internal temperature is at 140 degrees Fahrenheit, remove the springform from the water bath and place it on a cooling rack.
Here comes the hard part.
Allow the cake to cool on the rack to room temperature. Then place the cake (covered) into the the refrigerator for at least twelve hours. Yes, I know. You spent all this time prepping, whisking, baking and being gentle and now you can't even have a piece of cake???
Trust me. If you taste this thing as soon as it hits room temperature, you will want to throw it in the garbage. Imagine eating a used espresso puck. It's not quite that bad, but it is very shocking. Even if you're one of those 'hardcore' dark chocolate people, this is the kind of cake that needs some time to mellow. In point of fact, in the five day refrigerator lifespan of this cake, it only gets better with time. If I were planning on serving this to anybody, I would give it a 24 hour mellow in the refrigerator before I even considered foisting it on my friends.
That being said, once the requisite mellow-time has completed, this cake is insanely good. The chocolate obviously dominates the flavor, but is tempered with the butter. The butter also yields a better texture in the mouth and a quick melt. The eggs give just enough loft to keep your mind out of fudge territory and also play nicely in the texture department with the butter.
With regards to serving:
Unpack the cake from the springform and foil about a half hour ahead of serving time. Invert the cake onto a sheet of something that isn't sticky (waxpaper or parchment if you're quick enough) so that you can remove the parchment round from the bottom. Flip the cake back over onto the serving dish. If you are so inclined you can dust your cake with some powdered sugar or cocoa or top with fruit . I personally forgo the sugar/cocoa and go with a single raspberry and a mint leaf per slice, of which I make 16 for a 9" cake. Cutting the cake with a hot knife is beneficial and makes for a cleaner piece. You can use a regular kitchen knife run under hot water and dried before cutting.
For the health conscious (not that any of them made it past "chocolate" and "cake" in the same sentence...), the aforementioned 1/16th slice yields:
289 Calories (202 from Fat)
13.9g Saturated Fat
Vitamin A, Calcium and Iron
(Information taken from an online calorie calculator that I have no way of verifying for validity.)
Ok, breathe. It's going to be alright. You're not going to eat the whole thing by yourself, right? Right?