Baked Alaska is called an "omelette norvégienne" in French when made in the oval shape of an omelete. However, this dessert is done in a conical shape to emulate a volcano; hence its name. The top of a "volcano" is adorned with a hollowed-out lemon half that is filled (as soon as it comes out of the oven) with warm brandy, which is ignited, and the dessert is brought flaming to the table. The lemon mousseline cake, used here to hold the ice cream in the center, can be made a day or two ahead and stored in a plastic bag to keep it moist. If you prefer, a standard genoise or a sponge cake or pound cake can be substituted for the mousseline cake, as can ladyfingers.
The volcano bakes quickly, in 10 to 12 minutes, and should be brought to the table as it comes out of the oven. Although the egg whites shouldn't be beaten until the last moment, the ice cream and cake can be assembled ahead and kept covered in the freezer.
As soon as the cake comes out of the oven, sprinkle it with the confectioners' sugar, pour the warm cognac into the lemon shell, and ignite it. Bring the dessert to the table immediately. Spoon the flaming cognac onto the cake. using a spoon, scoop some of the soufflé, cake, and ice cream onto individual plates, and serve.
