After a lifetime of trying countless recipes for chocolate cake and chocolate icing, I’ve settled on the two recipes below. This makes the quintessential birthday cake, often requested.
The cake recipe is adapted from Dr. Peggy Polaneczky’s The Blog That Ate Manhattan, and came from her mother-in-law Irene’s vintage KitchenAid mixer booklet. Peggy added expresso powder for a flavor boost, but you can leave it out.
The chocolate ganache frosting recipe is from Gourmet, March 1999. Chef Ed Kasky used Guittard French-vanilla chocolate, but Ghirardelli bittersweet or semisweet chocolate is great too. You might think that a pound of chocolate is too much, but it is perfect. Note that the ganach has to cool up to an hour before it reaches the right consistency to apply to the cake.
For the cake
3 ounces unsweetened chocolate
¾ cup hot water
¾ cup butter
1 tablespoon instant expresso powder
2 cups brown sugar
2 ¼ cups UN-sifted cake flour
1 ½ teaspoons baking soda
¾ teaspoon baking powder
¾ teaspoon salt
¾ cup buttermilk
1 ½ teaspoons vanilla
Turn on oven to 350°F. You will need two 9-inch round cake pans. Even if you have nonstick pans, cut a 9-inch round of parchment paper and place on greased bottom of each pan. Grease the top of the paper and flour the pans.
Combine chocolate, expresso powder and hot water in a small saucepan. Cook over low heat, stirring constantly, until chocolate melts and is smooth. Set aside until mixture cools.
Cream butter in bowl for 1 minute at medium. Add sugar and beat at medium speed for 1-2 minutes. Stop and scrape sides of bowl using a rubber spatula. Turn to low-medium speed and add eggs, one at a time, beating after each addition till just incorporated, about 30 seconds, scraping the bowl when needed. Add cooled chocolate. Beat about 30 seconds at low-medium speed. Stop and scrape bowl.
In a separate bowl, whisk together cake flour, baking soda, baking powder, and salt; set aside. Combine buttermilk and vanilla. Turn to low speed and add one third of the flour mixture and beat till incorporated, just a few seconds. Still beating, pour in 1/2 the liquid, then another third of the flour mixture, the second half of the liquid, and finally the last third of the flour, beating as little as possible until just combined, stopping and scraping the sides when needed.
Pour batter into two greased and floured 9-inch round cake pans. (Before flouring, cut a 9-inch round of waxed or parchment paper and place on greased bottom of pan. Then grease the paper and flour pan.) Bake at 350°F for 25 to 30 minutes. Cool in pans 10 minutes, then invert pans on wire rack, remove waxed paper and let cakes cool completely before icing with chocolate frosting.
For the frosting
16 ounces (1 pound) bittersweet or semisweet chocolate, coarsely chopped
1 cup heavy cream
2 tablespoons sugar
2 tablespoons light corn syrup
2 ounces (1/2 stick) unsalted butter
Break chocolate into small pieces. In a 1.5 to 2-quart saucepan, bring cream, sugar, and corn syrup to a boil over moderately low heat, whisking until sugar is dissolved. Remove pan from heat and add chocolate, whisking until chocolate is melted. Cut butter into little pieces and add to frosting, whisking until smooth.
Transfer frosting to a bowl and cool, stirring occasionally, until spreadable. Depending on the chocolate, it may be necessary to chill frosting in the refrigerator (for less time than you might think) to get a spreadable consistency.
Spread frosting between cake layers and over top and sides. The cake keeps, covered and chilled, 3 days. Bring cake to room temperature before serving.