In your electric mixer, use the paddle attachment to cream the softened butter.
Slowly mix in the powdered sugar, only adding as much as your electric mixer can handle at a time.
Mix in the vanilla extract and 4 tbsp. of milk. If the mixture is too stiff, add more milk. I prefer a consistency of smooth peanut butter.
Refer to the instructions under this recipe card with how to divide up, color, and bag the frosting.