Preheat oven to 350 F. Line cupcake pan with paper liners.
Cream butter and sugar till very light and fluffy.
Add eggs one at a time, incorporating after each.
Combine the remaining dry cupcake ingredients (flour, baking powder, salt) in one bowl, and add alternating dry ingredients and beer until both are fully incorporated.
Fill cupcake liners most of the way to the top and bake for 20-25 minutes, until a toothpick comes out clean and the edges are golden brown.
Cool in the pan for 5 minutes, then remove to a cooling rack to cool completely.