Instructions

1. Beat powdered sugar and butter with an electric mixer until it's thoroughly combined and stiff. As a general rule, use about 1 cup of butter for each 1 pound box of confectioner's sugar to make roughly 3 cups of buttercream frosting. Keep the mixer running continuously as you add the remaining ingredients.

2. Blend in vanilla extract to taste, or you can simply use the Irish cream to add flavor. Use as much or as little vanilla as you wish, but as a general rule, use about 1 teaspoon of vanilla extract per pound of powdered sugar used.

3. Add Irish cream to the mixing bowl to taste; add about 1 tablespoon at a time. Taste the frosting after each tablespoon added. Buttercream frosting typically requires about 2 to 4 tablespoons of liquid to achieve a fluffy texture. Add more liquid if you want a stronger Irish cream flavor, but you might need to add more powdered sugar to compensate for any thinning out caused by adding the extra liquid.

4. Beat the ingredients for about two minutes or until you achieve a creamy texture with firm peaks. Place the back of a spoon against the surface of the frosting and pick it straight up to make a peak in the frosting. The frosting should be smooth and soft enough to form a peak easily, but firm enough so that it doesn't flop over. Add more powdered sugar to thicken the frosting, if needed, or add more Irish cream to thin the frosting.