I love this recipe, adapted from the charming Miette cookbook, for its deep chocolate flavor and ultra-moist texture. Note that you can substitute the buttermilk with whole milk mixed with a squeeze of lemon and left to ferment for a few minutes before adding to the batter. Ice the cake with the beautiful,fluffy meringue icing, or with your favorite icing. Makes 2 6-inch layer cakes using 6x3-inch pans, or about 24 cupcakes, or one 10-inch round.
1 1/4cupsnatural unsweetened cocoa powder, plus more for dusting
1 1/2teaspoonsbaking soda
1/2teaspoonbaking powder
3/4teaspoonkosher salt
2oz.chocolate, 70% cacao, chopped
1cupboiling water
1cupbuttermilk, room temperature
1/2teaspoonpure vanilla extract
2largeeggs, room temperature
1/2cupvegetable or other neutral oil
21/4cups sugar
For the Fluffy Pink Icing
1 1/2cups(10½ ounces) sugar
1/4teaspooncream of tartar
1/4cupwater
3large egg whites, room temperature
1teaspoonvanilla extract
Pink food coloring
Instructions
For the cake
Preheat the oven to 350°F. Grease cake pans and dust with cocoa powder. For cupcakes, line tins with paper cupcake liners.
In a medium bowl, whisk the flour, cocoa powder, baking soda, baking powder, and salt together.
In a small heatproof bowl pour boiling water over chocolate . Cool for 15 minutes, stirring until the chocolate melts.
In a separate bowl, stir the buttermilk and vanilla together.
Using a stand mixer fitted with the whisk attachment, whisk the eggs on high speed until light and foamy (about 2 minutes). On low speed, add the oil, then increase speed to thoroughly combine.
On low speed, add the chocolate mixture into the egg mixture, beat briefly. Add the buttermilk and vanilla mixture, beat briefly. Add the sugar and beat until the batter is smooth (about 2 minutes).
Remove the bowl from the stand mixer and gently fold in the dry ingredients with a rubber spatula until combined, pressing against the sides of the bowl to break down large lumps. The batter will be slightly lumpy. Pour the batter in the cake pans evenly, or in cupcake liners to ¾ full.
Bake for 55-65 minutes for the cake (about 30 minutes for the cupcakes) or until the tops spring back when lightly pressed and toothpick inserted comes out clean. Cool in the cake pans until just barely warm, then run a knife around the edges to loosen. Remove cakes from pans and cool on racks completely. For layer cake, slice 6-inch cakes in thirds across using a sharp bread knife. If freezing one cake, before cutting it into layers, wrap with double layers of plastic wrap and freeze.
For the icing
In the bowl of a stand mixer fitted with the whisk attachment, combine the egg whites and vanilla. Beat just until frothy, then stop.
In a small heavy saucepan, combine the sugar, cream of tartar, and water and bring to a boil. Continue boiling until the sugar reaches 230 degrees on a candy thermometer. Remove from the heat immediately and pour into a heatproof bowl or measuring cup.
Turn the mixer back on medium high speed, beating the egg whites. Slowly pour the sugar syrup into the whites (aim for between the whisk and the side of the bowl). Beat until the whites are very fluffy and cooled almost completely. Add small amounts of pink food coloring, if using, until you get the shade of pink you are after.
Dollop generously between the layers of the cake and on top. Icing the sides of the cake is optional; the double chocolate cake is moist enough to be exposed. For cupcakes, either pipe or simply spoon onto each cake.