Guinness Cupcake Recipe. If you only have one cupcake pan, you can let the extra batter sit while the first 24 cook, then remove the cupcakes, add extra liners and bake a second batch. Remove from heat and allow to cool.

Add eggs one at a. Melt 1 1/4 cups butter in a saucepan over low heat, add cocoa powder, and whisk until smooth. Once boiling, reduce to medium heat and allow to simmer until reduced down to 2/3 cup, about 20.