For the Cake
- 14 large egg whites (1 3/4 cups)
- 1 1/2 cups light-brown sugar, sifted
- 1 1/2 teaspoons cream of tartar
- 1 1/4 cups sifted cake flour (not self-rising)
For the Hot Fudge Sauce
- 1/4 cup unsweetened cocoa powder
- 1/2 cup sugar
- 1/2 cup light corn syrup
- 1/4 cup light cream or evaporated milk
- 1/8 teaspoon coarse kosher salt
- 1 1/2 tablespoons unsalted butter
- 1/2 teaspoon pure vanilla extract
- Preheat the oven to 350 degrees. In the bowl of a stand mixer fitted with a whisk attachment, beat egg whites and sugar on medium speed until foamy; add cream of tartar. Increase speed to high; beat egg whites until tripled in volume, stiff, and glossy. Transfer egg white mixture to a large bowl; fold in flour in three additions.
- Transfer batter to a piping bag fitted with a 1/2-inch to 3/4-inch round tip and pipe into ungreased mini angel food cake pans with removable bottoms. Smooth tops with an offset spatula. Run a knife through batter to pop air pockets. Bake until cakes are golden in color and spring back when gently pressed, about 25 minutes.
- Invert pans over the necks of glass bottles and allow cakes to cool, at least 1 hour. To remove cakes from pans, run a knife around sides and center tube of pans. Release cakes from sides and run a long knife along the bottom of the cakes, freeing them from the tube.
- Make the hot fudge sauce: Combine all ingredients except the vanilla in a saucepan and cook over medium heat, stirring constantly, until the mixture comes to a full boil. Boil the mixture briskly for 3 minutes, stirring occasionally, then remove from the heat and stir in the vanilla.
- Serve the cakes with hot fudge sauce and espresso ice cream.
The sauce can be stored in the refrigerator for 1 week. To reheat, place the container of sauce in a pan of hot (not boiling) water until the sauce warms and thins to a pouring consistency.