serves 4 to 6 (or 2 with leftovers)
I acquired my first 6-inch cake pans when I made a wedding cake for two friends in graduate school. Let’s just say that first cake was a good lesson in why professionally made cakes cost what they do. Luckily, it hardly mattered, as the bride and groom drank so many congratulatory shots that they barely noticed the cake, which the tipsy guests devoured with their hands when we ran out of forks.
Those pans have been put to good use ever since, and not just for wedding cakes. I also love using them to bake tiny layer cakes to feed four to six people. Or, for Valentine’s Day, two, with ample leftovers for breakfast the next morning.
When making a meringue buttercream, pay attention to the temperature of the ingredients. The butter really needs to be soft, pliable, and at room temperature, not melty, not hard. So take it out of the fridge an hour before you plan to make this. The egg whites must be completely cool, not warm, when you add the butter. Basically, the butter and egg whites should be the same temperature. If one is too cold, the mixture will curdle; too hot, and it will melt into soup. If you do get soup, set the bowl briefly in a bowl of ice water, then try beating it again. If it’s curdled, set the bowl in a bowl of very warm water and try beating it again. Fear not—broken buttercream can usually be rescued.
⅔ cup very hot coffee or water
⅓ cup unsweetened Dutch-process cocoa powder
¾ teaspoon kosher salt
4 large egg yolks (save the whites for the buttercream)
1 tablespoon vanilla extract
1½ cups cake flour
2 teaspoons baking powder
½ cup (1 stick) unsalted butter, at room temperature
1 cup sugar
4 large egg whites
1 cup sugar
¼ teaspoon kosher salt
1½ cups (3 sticks) unsalted butter, sliced, at room temperature
3 tablespoons good aged rum
1 cup chopped toasted pecans or purchased toffee bits (optional)
1. MAKE THE CAKE: Preheat the oven to 350°F. Grease and flour two 6-inch cake pans, or spray with baking spray. Cut parchment or waxed paper rounds to fit in the bottom of the pans, lay them down, and grease the paper.
2. In a small bowl, stir together the coffee and cocoa powder until smooth. Stir in the salt and let cool until barely warm to the touch. Whisk in the egg yolks and vanilla.
3. In a large bowl, whisk together the flour and baking powder.
4. In the bowl of an electric mixer fitted with the paddle attachment, beat the butter until fluffy. Add the sugar and beat until very light, about 5 minutes. Beat in a third of the cocoa mixture, followed by half the flour mixture, and beat well. Scrape down the sides of the bowl and beat again. Beat in another third of the cocoa mixture and then the remaining flour mixture. Scrape the sides again and add the remaining cocoa mixture. Beat until smooth.
5. Divide the batter evenly between the two cake pans and smooth the tops. Bake until the tops of the cakes are no longer shiny and wet looking, and a cake tester inserted into the center comes out clean, 30 to 35 minutes. Cool on wire racks before unmolding.
6. MEANWHILE, MAKE THE BUTTER RUM FROSTING: Put the egg whites, sugar, and salt into the clean metal bowl of your electric mixer (or any metal bowl, if using a handheld mixer). Bring a medium pot of water to a boil. Place the bowl of egg whites over the pot (make sure the bottom of the bowl does not touch the water) and whisk until the sugar has dissolved and the eggs are warm to the touch. Use pot holders if necessary to hold on to the bowl.
7. Remove the bowl from the heat and attach the bowl to your mixer. Beat the eggs with the whisk attachment until they are thick and cool, about 5 minutes. Beat in the butter, bit by bit, until the mixture is smooth and fluffy and buttercreamy. Beat in the rum. Use immediately, or store covered at room temperature for up to 24 hours. You might have to beat it again before using.
8. If the cakes are quite domed on top, use a knife to slice off the humps so the cake will be level (this is what professionals do to get perfectly even layers). Slice the cakes in half horizontally, and spread the buttercream between the layers, adding some of the chopped nuts or toffee bits if you like. Ice the cake, then cover with more of the nuts or toffee.