Preheat the oven to 350ºF.
In a small saucepan, warm the milk and 2 teaspoons butter together over medium-low heat. With an electric mixer fitted with a wire whip, beat the eggs and 1 cup of the sugar on medium-high speed until the mixture is pale yellow, thick, and has tripled in volume, about 8 minutes. With the mixer on low, beat in the warm milk mixture.
Sift the flour, baking powder, and salt into a medium-size mixing bowl. Fold the flour mixture into the egg mixture and blend thoroughly until smooth. Add the vanilla and mix gently.
Grease a 17 X 12-inch baking pan or jelly-roll pan with 2 tablespoons butter. Sprinkle evenly with the remaining 2 tablespoons sugar. Pour the cake batter into the pan, spreading it evenly. Bake until the cake springs back when touched, about 15 minutes. Cool for about 2 minutes, then gently flip it out onto a large wire rack or a large sheet of parchment paper. Let cool completely.
Cut the sponge cake into 4 equal pieces (cut in half vertically, then cut each half in two). Spread the softened chocolate ice cream on one layer. Top with a second piece of sponge cake. If the ice cream begins to melt, put the cake in the freezer for about 30 minutes. Spread the softened chicory ice cream over the second cake layer. Lay the third piece of cake on top and spread with the praline ice cream. Again, if the ice cream starts to melt, return the to the freezer to let it firm up. Top with the last piece of cake. Wrap the cake tightly with plastic wrap and freeze until firm, about 2 hours.
Beat the egg whites with an electric mixer until soft peaks form. Add the sugar and beat until stiff peaks form. Remove the cake from the freezer and, with a rubber spatula, carefully spread the meringue evenly over the tops and sides of the cake. With a small blowtorch, brown the meringue. To brown it in the oven, preheat the oven to 400ºF. Put the baked Alaska in the hot oven until the meringue is tinged golden brown, 2 to 4 minutes.
Cut the cake crosswise into 1 1/4-inch-thick slices and drizzle with the chocolate sauce to serve.
Yield: 1 cake; about 8 servings
Salmonella warning: Let’s talk about egg safety because I don’t want any of you out there to get sick. I personally love homemade fresh mayonnaise and I make it with fresh—and I mean FRESH—raw eggs. I’ve never had any trouble, but I want you to take some precautions. Always purchase your eggs from a reputable source, a place you can trust with your life. Don’t use eggs after the expiration date on the carton. Don’t go leaving your eggs in the backseat of your car while you’re out and about, and once you get home, keep the eggs in the refrigerator. I use eggs pretty quickly, so I don’t have to worry about keeping them too long at home. But I suppose there’s a tiny risk some nasty old salmonella could sneak into some eggs, so just be cautious about serving young kids or the elderly or to people who have health problems. Okay?