Betty Crocker's Peanut Butter Frosting

The most used cookbook I have is a Betty Crocker orange cookbook published in 1977 that I probably purchased about 1978.  This morning Emily called for one of her favorites out of that book, the peanut butter frosting.  That is our family's favorite frosting to go on a chocolate cake!  Super easy and inexpensive.

1/3 cup peanut butter (we always use creamy)
3 cups powdered sugar
1 1/2 tsp vanilla
1/4 to 1/3 cup milk  (this will depend on the spreading consistency you want)

Blend the peanut butter and sugar til creamy.  Stir in the vanilla and milk and then beat til smooth and of spreading consistency.