1Preheat oven to 300º F. Grease cake round pan with butter and line with parchment paper cut into circle. Over a double boiler, melt chocolate and butter.
2With mixer whisk egg whites, 1 teaspoon salt, and 3 oz of sugar on high for ~3 minutes until it holds medium stiff peaks.
3With mixer, whisk egg yolks, 1 teaspoon salt, 6 oz sugar, and 1 tablespoon vanilla for ~3 minutes, until pale. Whisk yolk mixture into chocolate mix. Fold egg white mixture.
4Pour batter into center of grease/lined cake pan, cover with foil. Bake in water bath for ~1 hour 20 min, or until the cake has the jiggle of a firm custard or jello.
5Let cool, and refrigerate for at least 4 hours, preferably overnight.
Note: If you want to remove from the pan after it has set, applying a minimal amount of heat to the bottom of the pan will allow the butter to melt and the cake.
*The chocolate we used for the E.A.T. dinner was Valrhona brand. Also, we cut this recipe in third to make the miniature slices. If using white chocolate, the cake is much less cooperative but adding 1 ½ cups of heavy cream should stabilize the dessert along with doubling the cook time.