Devil's Food Cake

DEVIL'S FOOD CAKE WITH BROWN SUGAR BUTTERCREAM

Serves 10 - Active time: 1 h - Start to finish: 2 h

CAKE
1 cup boiling water
3/4 cup unsweetened cocoa powder (not Dutch process)
1/2 cup whole milk
1 teaspoon vanilla
2 cups all-purpose flour
1 1/4 teaspoons baking soda
1/2 teaspoon salt
2 sticks (1 cup) unsalted butter, softened
1 1/4 cups packed dark brown sugar
3/4 cup granulated sugar
4 large eggs
Brown sugar buttercream (see recipe below)

Preheat oven to 350°F. Butter 3 (8- by 2-inch) round cake pans and line bottoms of each with rounds of wax or parchment paper. Butter paper and dust pan with flour, knocking out excess.

Whisk together boiling water and cocoa powder in a bowl until smooth, then whisk in milk and vanilla.

Sift together flour, baking soda and salt in another bowl.

Beat together butter and sugars in a large bowl with an electric mixer until pale and fluffy, then add eggs one at a time, beating well after each addition. Beat in flour and cocoa mixtures alternately in batches, beginning and ending with flour mixture (batter may look curdled).

Divide batter among pans, smoothing tops. Bake in upper and lower thirds of oven, switching position of pans halfway through baking, until a testercomes out clean and layers begin to pull away from sides of pans, 20 to 25 minutes total. Cool layers in pans on racks 10 minutes, then invert onto racks, remove wax paper, ad cool completely.

Put 1 cake layer, rounded side up, on a cake plate and spread with about 1 cup buttercream. Top with another cake layer, rounded side up, and spread with another cup buttercream. Top with remaining cake layer and frost top and sides of cake with remaining buttercream.

Notes: This batter can be baked in 2 (9- by 1-inch) round cake pans 25 to 30 minutes, in a 13- by 9- by 2-inch pan 35 to 40 minutes, in a 12-cup bundt pan 35 to 40 minutes, or in 24 (1/2-cup) muffin cups 20 to 25 minutes.

BROWN SUGAR BUTTERCREAM

Makes about 3 1/2 cups - Active time: 15 min - Start to finish: 25 min

3 large egg whites at room temperature
1/8 teaspoon salt
1 cup packed dark brown sugar
1/2 cup water
1/2 teaspoon fresh lemon juice
3 sticks (1 1/2 cups) unsalted butter, cut into pieces and softened
2 teaspoons vanilla

Combine egg whites and salt in a large bowl.

Stir together brown sugar and water in a small heavy saucepan and bring to a boil over moderately high heat, washing down side of pan with a pastry brush dipped in water. When sugar syrup reaches boil, start beating whites with an electric mixer at medium-high speed until frothy, then add lemon juice and beat at medium speed until whites just hold soft peaks (do not beat again until sugar syrup is ready).

Meanwhile, put candy thermometer into sugar syrup and continue boiling until syrup reaches 238-242°F. Immediately remove from heat and pour into a heatproof 1-cup glass measure. Slowly pour hot syrup in a thin stream down side of bowl into egg whites, beating constantly at high speed. Beat meringue, scraping down bowl with a rubber spatula, until meringue is cool to the touch, about 6 minutes. (It's important that meringue is properly cooled before proceeding).

With mixer at medium speed, gradually add butter 1 piece at a time, beating well after each addition until incorporated (if meringue is too warm and buttercream looks soupy after some of the butter is added, briefly chill bottom of bowl in a large bowl filled with ice water for a few seconds before continuing to beat in remaining butter). Continue beating until buttercream is smooth (mixture may look curdled before all of butter is added, but will come back together before beating is finished). Add vanilla and beat 1 minute more.