1/2 c. butter
2 1/4 c. brown sugar
1/2 c. milk
3/4 c. peanut butter
1 tsp. vanilla extract
3 1/2 c. powdered sugar

In a medium sauce pan, melt butter; stir in brown sugar and milk. Bring to a boil, stirring constantly; boiling for 2 minutes. Remove from heat, stir in peanut butter and vanilla. Pour mixture over powdered sugar in a large mixing bowl; beat until smooth. Pour into an 8 by 8 inch dish; chill until firm, then cut into small squares.