Guinness Cupcakes with Guinness Frosting

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Grease two 12-cup muffin tins or line cups with paper liners.

Step 2
Whisk stout beer, milk, vegetable oil, and vanilla extract together in a bowl until evenly blended. Beat in eggs 1 at a time, beating well after each addition. Mix in sour cream. Whisk together flour, sugar, cocoa powder, and baking soda in a separate bowl. Gradually mix the flour mixture ingredients into the beer mixture.

Step 3
Spoon cupcake batter into the prepared muffin cups, filling each 3/4 full.

Step 4
Bake in the preheated oven until cupcakes are risen and set in the middle but still soft and tender, about 25 minutes. Cool in the tins, then transfer to a wire rack to cool completely, about 1 hour.

Step 5
Whisk cocoa powder and stout beer together in a bowl. Beat in butter and cream cheese using an electric mixer until well combined. Gradually beat in confectioners' sugar, 1 cup at a time, until frosting has desired sweetness. Spread or pipe frosting onto cooked cupcakes.