I have adapted this recipe from Rose Levy Beranbaum. She says this is her favorite way to eat chocolate. It is baked at a high temperature for a short time in a water bath delivering what she calls a result that is like the creamiest truffle wedded to the purest chocolate mousse. Be sure to serve it a room temperature, not chilled. Baking the Oblivion in a water bath keeps the texture creamy throughout. When this cake is served at room temperature, you get a rush of chocolate from the moment it enters your mouth. The full flavor of chocolate can best be appreciated only in a softened state. (A chocolate bar, for example, has to start melting in the mouth before the flavor comes through.) The butter and eggs do not distract. Instead they contribute structure and the desired creamy texture.
CAKE RECIPE HELP

INGREDIENTS

(all at room temperature):

bittersweet chocolate: 1 pound or 5 1/3 (3-ounce) bars or 454 grams

unsalted butter: 1 cup or 1/2 pound or 227 grams

6 large eggs: 1 1/4 scant cups or 10.5 ounces or 300 grams (weighed without shells)



Beranbaum note: Two of my favorites are Lindt Courante and Tobler extra bittersweet. If using Courante chocolate, add 1/3 cup (2.25 ounces/66 grams) sugar to the eggs while beating. If using extra bittersweet, add 3 tablespoons (1.5 ounces/37 grams) sugar.


INSTRUCTIONS
Prepare pan: One 8-inch springform pan at least 2 1/2 inches high, buttered and bottom lined with buttered parchment or wax paper; outside of pan wrapped with a double layer of heavy-duly foil to prevent seepage. Finished height of cake is 1 1/2-inches.
One 10-inch cake pan or roasting pan to serve as a water bath.
NOTE: An 8- by 2-inch solid cake pan can be used instead of a springform, or an 8- by 3-inch pan. To unmold, run a thin spatula around the sides, place the pan on a heated burner for 10 to 20 seconds, moving it back and forth, and then invert. If the cake does not release, return it to the hot burner for a few more seconds.

Heat the oven to 425 degrees F.

In large metal bowl set over a pan of hot, not simmering, water (the bottom of the bowl should not touch the water) combine the chocolate and butter and let stand, stirring occasionally, until smooth and melted. (The mixture can be melted in the microwave on high power, stirring every 15 seconds. Remove when there are still a few lumps of chocolate and stir until fully melted.)

In a large bowl set over a pan of simmering water heat the eggs, stirring constantly to prevent curdling, until just warm to the touch. Remove from the heat and beat, using the whisk beater, until triple in volume and soft peaks form when the beater is raised, about 5 minutes. (To insure maximum volume if using a hand mixer, beat the eggs over simmering water until they are hot to the touch, about 5 minutes. Remove from the heat and beat until cool.)

Using a large wire whisk or rubber spatula, fold 1/2 the eggs into the chocolate mixture until almost incorporated. Fold in the remaining eggs until just blended and no streaks remain.
NOTE: For a moist airy texture, be sure to add beaten eggs to chocolate mixture and not the chocolate to the eggs. 

Finish by using a rubber spatula to ensure that the heavier mixture at the bottom is incorporated. Scrape into the prepared pan and smooth with the spatula. Set the pan in the larger pan and surround it with 1 inch very hot water. Bake 5 minutes. Cover loosely with a piece of buttered foil and bake 10 minutes. (The cake will look soft, but this is as it should be.)

Let the cake cool on a rack 45 minutes. Cover with plastic wrap and refrigerate until very firm, about 3 hours.

To unmold: Have ready a serving plate and a flat plate at least 8 inches in diameter, covered with plastic wrap. Wipe the sides of the pan with a hot, damp towel.
NOTE: Use the plastic-wrapped plate when unmolding to protect the surface of cake if you're not planning to use a topping.

Run a thin metal spatula around the sides of the cake and release the sides of the springform pan. Place the plastic-wrapped plate on top and invert. Wipe the bottom of the pan with a hot, damp towel. Remove the bottom of the pan and the parchment. Reinvert onto the serving plate.

Tip: If you have an oven with a pilot light, it can save you a lot of time. The night before baking, place the chocolate and butter in the oven along with the eggs still in their shells in another mixing bowl. (Eggs should weigh about 12 ounces/340 grams.) The next morning, the chocolate and butter will be fully melted and the eggs the perfect temper- ature. Stir the chocolate and butter until smooth and be sure to remove it and the eggs from the oven before preheating oven!

SERVE
Room temperature. Cut into narrow wedges with a thin sharp knife that has been dipped in hot water.

STORAGE

2 weeks refrigerated. Do not freeze because freezing changes the texture.


Adapted from The Cake Bible by Rose Levy Beranbaum – posted with permission