These can be made to any size you wish, since there are various types of paper cupcake holders on the market.
Ingredients
1/2 cup peanut butter
1/3 cup shortening
1 tsp. vanilla
1 1/2 cups brown sugar
2 eggs
2 cups flour
2 tsps. baking powder
1/2 tsp. salt
1 cup milk
Method
Cream together peanut butter, shortening and vanilla.
Add brown sugar and beat until light and fluffy.
Add eggs one at a time and beat well.
Sift together dry ingredients and add alternately with milk.
Place paper bake cups in muffin pans and fill half full. Bake at 375 degrees F. for 20 minutes.
Peanut butter can be spread on the tops as a frosting.