For generations, chocolate was a luxury food item that families stretched their budgets to afford, making its presence on our tables an expression of affluence. In flush times, bakers added extra chocolate to standard chocolate cake batter, which yields a deep, dark fudge cake known as devil’s food cake. German chocolate cake, ennobled by a caramel, coconut and pecan filling, was known as the “rich people’s cake,” Wilbert Jones explained in “Mama’s Tea Cakes: 101 Delicious Soul Food Desserts.”
Chocolate-potato cake is an heirloom recipe, popular among early twentieth-century cooks from Kentucky to California, that might seem like a purely make-do improvisation for stretching valuable chocolate. But in fact, stirring mashed potatoes into the batter is a brilliant way to give the cake extra moistness. Fragrant with ground cinnamon, cloves and nutmeg and studded with nuts, it may remind some of Texas sheet cake. I was not surprised to find that some cooks tossed raisins in the mix; African American families in California were active grape growers who marketed raisins for profit.
But back to the devil’s food cake: This quick and easy recipe is a departure from standard mixtures that start by creaming together butter and sugar — what the old cooks meant when they said, “Bake a cake in the usual way.” Coffee gives the batter a subtle richness. The cake is delicious topped with billows of fluffy white marshmallow frosting or a light buttercream or a chocolate cream cheese frosting. Baked in layers, it will make a lovely statement on your next special-occasion dessert table. A sheet cake is easier to serve and is de rigueur at the annual Martin family reunion.
For the chocolate cream cheese frosting:
In a stand mixer fitted with the paddle attachment, beat the cream cheese and butter until light and fluffy, about 3 minutes. Scrape down the sides of the bowl. Gradually beat in the powdered sugar and cocoa, blending in well between additions. Beat in the vanilla and enough milk to make a smooth frosting. Mix until light and fluffy, and it’s ready to use.
For the cake:
Preheat the oven to 350 F. Lightly coat two 9-inch round cake pans or a 13- by 9-inch pan with cooking spray or shortening. Cut parchment paper to fit the bottom of the pan(s). Coat again with cooking spray or shortening. Dust lightly with flour, then tap the edges of the pan to remove and discard excess flour.
In a large bowl, whisk together the flour, sugar, cocoa, baking soda and salt. In a separate bowl, combine the oil, buttermilk, eggs and vanilla. Using an electric mixer with the paddle attachment, beat the wet ingredients into the flour mixture on medium speed until the batter resembles hot chocolate, about 2 minutes. Stir in the boiling hot coffee and beat until well blended; the batter will be thin.
Pour the batter into the pans and bake until a wood pick inserted in the center comes out clean, 30-35 minutes. Cool the cake in the pans on wire racks for 10 minutes, then turn the cake out onto wire racks to cool completely.
When cool, frost with chocolate cream cheese frosting.