Blackout Cake


  • 1⁄2 cup unsweetened Droste cocoa powder
  • 2 TBS boiling water
  • 2 oz. unsweetened chocolate, chopped
  • 3⁄4 cup milk
  • 1 cup (2 sticks) unsalted butter, slightly softened
  • 2 cups sugar
  • 4 large eggs, separated
  • 2 tsp. vanilla extract
  • 2 cups all-purpose flour
  • 1 tsp. baking powder
  • 1 tsp. baking soda
  • 1 tsp. salt


  • 1 TBS plus 1 3⁄4 tsp. unsweetened Droste cocoa powder
  • 2 cups boiling water
  • 3⁄4 cups plus 1⁄2 tsp. sugar
  • 1 oz. bittersweet chocolate, chopped
  • 2 TBS cornstarch dissolved in 1 TBS cold water
  • 1⁄4 tsp. salt
  • 1 tsp. vanilla extract
  • 2 TBS unsalted butter


  • 12 oz. semisweet chocolate, chopped
  • 12 TBS (1 1⁄2 sticks) unsalted butter
  • 1⁄2 cup hot water
  • 1 TBS light corn syrup
  • 1 TBS vanilla extract

Preheat the oven to 375 degrees. Butter and lightly flour two 8-inch round cake pans. To make the cake: place the cocoa in a small bowl, whisk in the boiling water to form a paste and set aside. Combine the chopped chocolate and milk in a saucepan over medium heat and stir frequently until the chocolate melts, about 3 minutes. Remove from heat. Whisk a small amount of the hot chocolate milk into the cocoa paste to warm it. Whisk the cocoa mixture into the milk mixture. Return the pan to medium heat and stir for 1 minute. Remove and set aside to cool until tepid. In a mixing bowl, cream the butter and sugar together. Add the vanilla and beat in the egg yolks, one at a time. Slowly stir in the chocolate mixture. In a separate bowl, combine the flour, baking powder, baking soda and salt. Using a spatula or wooden spoon, slowly fold in the flour mixture to the chocolate mixture until just mixed. In another bowl, whisk the egg whites until soft peaks form. Gently fold the egg whites into the batter. Divide the batter between the prepared pans. Bake until a toothpick inserted in the center comes out clean, 35 to 45 minutes. Cool the cakes in the pans on racks for about 15 minutes. Gently remove the cakes from the pans and continue to cool. While the cake is baking, make the filling: Combine the cocoa and boiling water in a small saucepan over low heat. Stir in the sugar and chocolate. Add the dissolved cornstarch paste and salt to the pan and bring to a boil stirring constantly. Boil for 1 minute. Remove from heat and whisk in vanilla and butter. Transfer the mixture to a bowl, cover and refrigerate until cool. Make the frosting: Melt the chocolate in a double boiler over hot, not simmering, water, stirring until smooth. Remove the top of the double boiler from the heat and whisk in the butter one tablespoon at a time. Return the top to the heat, if necessary, to melt the butter. Whisk in the hot water all at once and whisk until smooth. Whisk in the corn syrup and vanilla. Cover and refrigerate for up to 15 minutes before using. Assemble the cake: Use a sharp serrated knife to slice each cake layer horizontally in half to form four layers. Set one layer aside. Place one layer on a cake round or plate. Generously cover the layer with one-half of the filling. Add the second layer and repeat. Set the third layer on top.