Repertoire Chocolate Cake

Makes one 8-inch layer cake

THERE AREN’T a whole lot of things that I am dogmatic about, but layer cakes are one of them (as evidenced by these back-to-back cake recipes). Baking a layer cake is an act of love, and, more than almost any other recipe in this book, this chocolate cake is something I think everyone should have in his or her repertoire.

It’s an ideal birthday cake and I believe (again with the cake dogma) that birthday cakes should always be made at home. Since I’ve begun doing the birthday-party circuit with my own children, I’ve seen a lot of beautiful cakes—professional bakery cakes piped with buttercream rosettes, sheet cakes topped with mises-en-scène that would put some off-Broadway sets to shame. It’s not that those cakes don’t taste good; I often eat more than my fair share. But I have a deep fondness for leaning homemade layer cakes, for cupcakes smeared hastily with frosting and showered with colored sprinkles. To me, the lifelong recipient of a homemade birthday cake every year (thanks, Mom), those funky cakes are love made visible.

I have made dozens and dozens of chocolate cakes in my life, but this recipe is the only one I’ll use from now on. It has a delicate crumb and is almost jet black because of the generous amount of cocoa powder. The silky chocolate frosting seems like it will be impossibly rich but it’s just right, and it spreads so easily that even if this is the first cake you’ve ever frosted, it’s going to look beautiful.

The cake can also be baked as cupcakes; reduce the baking time to 18 minutes. It will make 18, enough for whatever school function or potluck you’ve promised to supply dessert for. Any extra frosting can be frozen.

1 cup unsalted butter, plus more for greasing the pans

12 tablespoons (2½ ounces) Dutch process cocoa powder

2 teaspoons instant espresso powder

⅔ cup boiling water

⅔ cup milk

2 cups cake flour

1 teaspoon baking soda

½ teaspoon baking powder

½ teaspoon kosher salt

2 cups sugar

3 eggs, at room temperature

1 teaspoon vanilla extract

FOR THE FROSTING:

1 cup heavy cream

8 ounces good-quality milk chocolate, chopped

8 ounces semisweet chocolate (64 percent), chopped

1 cup unsalted butter, at room temperature, cubed

Pinch of kosher salt

Chocolate sprinkles (optional)

Place a rack in the center of the oven and preheat the oven to 350°F. Butter two 8-inch round cake pans and line the bottom of each pan with parchment paper. Butter the parchment and dust the pan with cocoa powder; tap out the excess.

In a medium bowl, whisk together the cocoa, espresso powder, and boiling water. Whisk in the milk and let cool.

Sift together the cake flour, baking soda, baking powder, and salt. Set aside.

In an electric mixer fitted with the paddle attachment, beat the 1 cup butter and sugar until light and fluffy, about 5 minutes. Beat in the eggs one at a time, then beat in the vanilla. With the mixer on low speed, gradually pour in the cooled cocoa mixture and mix until fully incorporated. Gradually add the sifted dry ingredients to the chocolate mixture, mixing until just combined.

Pour the batter into the prepared pans. Bake for 15 minutes, rotate the pans, and bake for an additional 15 to 20 minutes, until a toothpick inserted into the center of the cake comes out clean. Remove the layers from the oven, and allow them to cool in pans for 15 minutes on a cooling rack. Carefully run a small offset spatula around the edges of the layers to loosen them from the pans. Remove them from the pans, and invert onto a wire rack. Let cool completely, about 1 hour. The cake can be made a day ahead; once cool, wrap each layer tightly in plastic wrap and refrigerate. The cooled layers can also be tightly wrapped and frozen for up to a month.

WHILE THE LAYERS COOL, MAKE THE FROSTING: Heat the cream in a small saucepan until bubbles form at the edges of the pan. Put the chocolate in a large heatproof bowl and pour the cream over; let stand 5 minutes, then whisk until smooth. Whisk in the cubed butter until the mixture is smooth and silky. Let cool at room temperature; the frosting will thicken but remain spreadable. The frosting can be made up to a week ahead and refrigerated; let come to room temperature before using.

If the tops of the cake layers have mounded unevenly, level them by removing the top crust with a long serrated knife. With a serrated knife, cut each cake layer in half horizontally to create two thin layers.

Place one cake layer on a cake stand or large plate and top with about ½ cup of the frosting, spreading in an even layer all the way to the edges. Top with a second cake layer and another ½ cup frosting. Repeat with the next 2 layers. With an offset spatula, spread the remaining frosting in a thick layer over the top and sides of the cake, using the tip of the spatula to create decorative curls and swirls. Decorate the top and sides of the frosted cake with sprinkles, if using, pressing lightly to adhere. Refrigerate the cake at least 15 minutes before serving; if you’re refrigerating the cake longer, allow some time for the frosting to come to room temperature before serving. With a sharp knife, cut the cake into thick wedges.