Peanut Butter Icing

3 cups powdered sugar
1/2 cup peanut butter
1/2 teaspoon vanilla
1/4 cup milk (may require more)

Mix sugar and peanut butter.

Stir in vanilla and a tablespoon of milk.
Gradually beat in just enough of the remaining milk until smooth. 

OR

Substitute 1/2 to 1/3 of the amount of shortening for peanut butter from your regular icing recipe