2 c. sugar
1/2 c. peanut butter
2/3 c. sweet milk
1/2 c. shortening
2 tsp. vanilla

Combine sugar and peanut butter; add melted shortening and milk. Boil for 2 minutes, stirring constantly. Remove from heat; add vanilla and beat until creamy. If too thick, add more milk. Spread on cooled cake layers.