Ingredients
- 2 cups all-purpose flour
- 1 ½ teaspoons baking powder
- ½ teaspoon baking soda
- ¼ teaspoon salt
- ¾ cup unsweetened cocoa powder
- 1 ½ cups granulated sugar
- ½ cup (1 stick) unsalted butter, softened
- ¾ cup vegetable oil
- 3 large eggs
- 1 teaspoon vanilla extract
- 1 cup buttermilk
- ½ cup strong brewed coffee, cooled
- ¼ cup dark rum
Rum Syrup for Soaking
- ¼ cup dark rum
- 2 tablespoons granulated sugar
- 2 tablespoons water
Chocolate Buttercream Frosting
- 1 cup unsalted butter, softened
- 1 ¾ cups powdered sugar, sifted
- ½ cup unsweetened cocoa powder
- ¼ cup heavy cream
- 1 teaspoon vanilla extract
- Pinch of salt
Instructions
- Preheat oven to 350°F (175°C). Grease and flour two 8-inch round cake pans.
- Sift together dry ingredients: flour, baking powder, baking soda, salt, cocoa powder.
- Beat butter, oil, and sugar until light and fluffy. Add eggs one at a time, mixing thoroughly after each. Stir in vanilla.
- Alternately add dry ingredients and buttermilk to the butter mixture, starting and ending with dry. Mix just until combined.
- Stir in cooled coffee and rum.
- Divide batter evenly between pans. Bake 30–35 minutes or until toothpick comes out clean. Cool 10 minutes, then transfer to wire racks.
- Make syrup: Heat rum, sugar, and water until the sugar dissolves; cool. Brush syrup generously over warm cake layers.
- Make frosting: Beat butter until creamy, add powdered sugar and cocoa. Beat in heavy cream, vanilla, and salt until fluffy.
- Assemble cake, frosting between layers, top, and sides. Decorate as desired.