School Cafeteria Peanut Butter Bars

1/2 C. creamy peanut butter 1 stick butter or margarine 1 C. self rising flour 1 1/2 C. white sugar 2 large eggs 1 T. vanilla extract Frosting: 1 1/2 C. confectioners sugar 2 T. creamy peanut butter 2 T. milk 1 tsp. vanilla Put the peanut butter and butter in a saucepan over low heat to melt, do not let it boil, just warm and melt. Remove from heat and stir in the sugar, eggs and vanilla. Add the flour and stir to combine well. Spread evenly into a 13x9" sheet cake pan. Bake at 350 degrees for 25 minutes. Cool completely and frost. Frosting: Whisk together all ingredients and spread over bars.