From the book Sky High: Irresistible Triple-Layer Cakes
Vanilla Buttermilk Cake with Instant Fudge Frosting
Yield: One 8" triple layer cake; serves 12-16
4 whole eggs
2 egg yolks
2 teaspoons vanilla extract
1 1/4 cups buttermilk
3 cups cake flour
2 cups sugar
4 1/2 teaspoons baking powder
1/2 teaspoon salt
2 sticks (8 ounces) unsalted butter, at room temperature
1. Preheat the oven to 350° F. Butter the bottoms and sides of three 8-inch round cake pans or spray to coat with vegetable oil. Line the bottom of each pan with a round of parchment or waxed paper and grease the paper.
2. Put the eggs and yolks in a medium mixing mixing bowl, add the vanilla and 1/4 cup of the buttermilk. Whisk to blend well.
3. Combine the flour, sugar, baking powder, and salt, in a large mixer bowl; whisk to blend. Add the butter and the remaining 1 cup buttermilk to these dry ingredients and with the mixer on low, blend together. Raise the mixer speed to medium and beat until light and fluffy, about 2 minutes.
4. Add the egg mixture in 3 additions, scraping down the side of the bowl and mixing only until thoroughly incorporated. Divide the batter among the 3 prepared pans.
5. Bake the cake layers for 28-32 minutes, or until a cake tester or wooden toothpick inserted into the center comes clean and the cake begins to pull away from the sides of the pan. Let the layers cool in the pans for 10 minutes; then carefully turn out onto wire racks, peel of the paper liners, and let cool completely.
6. To assemble the cake, place one layer, flat side up, on a cake stand or serving plate. Spread 3/4 cup of the Instant Fudge Frosting over the layer right to the edge. Repeat with the next layer. Place the last layer on top and use all but 3/4 cup of the frosting to cover the top and sides of the cake. With an offset palette knife or spatula, smooth out the frosting all over. Place the remaining 3/4 cup frosting in a pastry bag fitted with a medium star tube and pipe a shell border around the top and bottom edges of the cake.
Instant Fudge Frosting
6 ounces unsweetened chocolate, melted and cooled
4 1/2 cups confectioners' sugar (no need to sift)
3 sticks (12 ounces) unsalted butter, at room temperature
6 tablespoons half-and-half
1 tablespoon vanilla extract
A large food processor is the best piece of equipment to use for the frosting recipe. It whips up the perfect fudge frosting, and there is no need for a boiled syrup.
Place all of the ingredients in a food processor and pulse to incorporate. Then process until the frosting is smooth.
1. For the ultimate version of this frosting, I used my favourite Belgian bittersweet chocolate: Callebaut Chocolate - Pure - Bittersweet - 1 kg
2. For a mocha frosting, you can add 1/4 teaspoon (or more, to taste) instant espresso powder.
3. If you don't have a food processor, you can make this frosting in your mixer by beating the butter and confectioners' sugar with the flat beater for about a minute on low speed, followed by another minute on medium-high speed. Add the remaining ingredients and beat on medium-high speed for about 2 minutes, until fluffy.
4. Frosting is best used immediately, but holds up nicely on the cake once frosted.
5. Finished cake keeps best in a cake-saver at room temperature for up to 3 days.