This cake is a prime example of Joe Pastry’s Inverse Law of Ingredient Dynamics, which states that as the number of ingredients in a given recipe goes down, the importance of the quality of those ingredients and the techniques by which they are handled goes up. There’s a great misconception out there that because a flourless cake isn’t leavened, it’s basically fool-proof. However as all of us who’ve eaten chalky homemade flourless cakes can attest, they can be, and usually are, messed up. Thus it’s important to pay attention to the details.
So then, first thing is to get the oven on to 325. Set a large pot of water simmering for your water bath, and turn the heat on under your double boiler. Then, beginning with whatever blend of semi- and extra-bittersweet chocolates you wish, lay them down on your cutting board…
…and with the biggest, heaviest chef’s knife you own, carefully chop it.
Next, get your cake pan ready for its nice warm bath. Prepare your 9″ springform pan (instructions are over to the right). Lay it on a sheet of tin foil, gather the foil up around the sides, and press it to form. This is where the double-width foil of a professional kitchen comes in very handy, but I don’t keep a two-ton roll like that hanging around (at least not anymore).
You want the foil to come at least half way up all sides of the pan like so:
What you’re making is essentially a little boat. Now then, put your eggs in the bowl of a mixer fitted with a whip and turn the mixer on medium-high (this is one instance where your eggs don’t need to be at room temperature…in fact cold eggs are preferred since they whip up into a “finer” foam).
While the machine is running, put your butter and chocolate in the double boiler (yes that’s expensive Euro-butter…remember what I said about ingredients?). Very gently melt them together. It should take about ten minutes.
…by which time your eggs should be very foamy and light, several times their original volume. About like so:
Now all you need to do is combine them, but gently since those bubbles are all the leavening this cake will have. Thus you’ll want to fold them in (instructions for that are also over there on the right). Since the mixture needs to be lightened before real folding can happened, begin by adding a third of the egg foam…
…and simply stirring it in until it looks like so:
Streaks are OK. So then, add another third…
…and this time fold like you mean it. Until it looks like so:
Add the last of the egg…
…and keep folding diligently until just a few streaks remain.
Pour your batter into your prepared pan/boat…
…and insert it into your expensive Continental bain marie. Mine I have cleverly disguised as a cheap speckled tin roasting pan, so as not to make all of you feel inadequate.
Add your hot water, enough to come half way up the side of the cake pan.
Carefully insert the whole thing into your oven on the bottom rack (alternately, you can wait to fill the water bath until after it’s in the oven). Bake at 325. I set my thermometer for fifteen minutes, then check the temperature every five or so minutes afterward to make sure I don’t overshoot my target temperature of 140 degrees. A digital thermometer comes in very, very handy for this.
Ah yes, there we go, right about 140. You’ll notice that the cake is still very pudding-like in the middle at this point. Never fear, it will firm. Remove it from the water bath and place it on a rack to cool. Once it’s cooled down to room temperature, place it in the fridge to chill overnight.