1 cup Guinness or other stout beer
10 tablespoons unsalted butter
¾ cup Black Onyx Cocoa Powder
2 cups sugar
¾ cup sour cream
2 large eggs
1 tablespoon vanilla extract
2 cups all-purpose flour
2 ½ teaspoons baking soda
Preheat oven to 350 degrees. Butter a single 9-inch spring-form pan and line with parchment paper or 2 8-inch cake pans.
In a large saucepan, combine Guinness and butter and heat at medium-low heat just until butter melts and then remove from heat. Add dark cocoa powder and sugar and blend well.
In a small bowl, combine sour cream, eggs and vanilla; mix well. Add to Guinness mixture. Add flour and baking soda and blend until smooth.
Pour into prepared pan(s), and bake until risen and firm, about 45-50 minutes for a single spring-form pan and about 30-35 minutes if using 2 8-inch pans. Cake is done when a toothpick inserted in the center comes out clean. It is important not to over bake as it will make the cake dry. Place pan on a wire rack and cool completely in pan before removing and frosting. Cutting the cake into layers before frosting isn’t really necessary and honestly it retains moisture if you don’t.