Brooklyn Blackout Cake
Recipe Mari Loewen, Photo Stacey Brandford
Ingredients
½ cup unsweetened Dutch-process cocoa
¼ cup boiling water
2 ounces unsweetened chocolate, chopped
¾ cup milk
2 cups sugar
2 sticks unsalted butter, slightly softened, plus 2 tablespoons for the cake pans
4 eggs, separated
2 teaspoons vanilla
2 cups flour, plus 1 tablespoon for the cake pans
1 teaspoon baking powder
1 teaspoon salt
1 teaspoon baking soda
Filling
2 tablespoons unsweetened Dutch-process cocoa
2 cups boiling water
¾ cup plus 1 tablespoon sugar
1 ounce bittersweet chocolate, chopped
¼ cup cornstarch
1 tablespoon cold water
¼ teaspoon salt
1 teaspoon vanilla
2 tablespoons butter
Frosting
12 ounces semisweet chocolate, chopped
¾ cup unsalted butter
½ cup hot water
1 tablespoon corn syrup
1 tablespoon vanilla
Preparation
Heat oven to 375°F. Whisk cocoa with boiling water to form a paste. In a saucepan over medium heat, warm milk and chocolate, stirring until melted. Whisk a little hot milk into cocoa paste, then whisk cocoa mixture back into saucepan. Return to heat, stir 1 minute, remove and cool until tepid.
Cream butter and sugar. Beat in egg yolks one at a time, then vanilla. Stir in chocolate mixture. Whisk flour, baking powder, baking soda, and salt, then gently mix into batter. Whip egg whites to soft peaks and fold into batter.
Butter and flour two 8-inch round pans. Divide batter between pans and bake 45 minutes. Cool 15 minutes, then turn out and cool completely.
For filling, heat cocoa and boiling water over low heat. Add sugar and chocolate. Whisk cornstarch with cold water, add to pan with salt, bring to a boil, and cook 1 minute, stirring. Remove from heat, whisk in vanilla and butter, transfer to bowl, and chill until cool.
For frosting, melt chocolate in a double boiler. Whisk in butter one tablespoon at a time. Whisk in hot water, corn syrup, and vanilla until smooth. Chill 20–30 minutes.
To assemble, slice cakes horizontally to make four layers. Set one layer aside. Layer cake with filling between two layers, add third layer, and frost top and sides. Chill 10 minutes. Crumble remaining layer, apply a second coat of frosting, press crumbs onto cake, and serve within 24 hours.
