Servings: About 3 cups, enough for 1 dozen cupcakes

1 cup butter, room temperature 1 cup butter, room temperature
3 cups powdered sugar 3 cups powdered sugar
3 tablespoons Bailey's Irish Cream 3 tablespoons Bailey's Irish Cream

In a stand mixer fitted with a paddle attachment, cream the butter on high speed until very pale. Scrape down the sides of the bowl.
With the mixer running on low speed, add the powdered sugar. Beat to combine. Scrape down the sides of the bowl and add the Bailey's. Beat again.
Turn the mixer speed to high and beat for about 10 minutes, until the buttercream is light and fluffy.