Over low heat, melt butter or margarine in a medium saucepan and add peanut butter. Stir until smooth.
Add sugar, graham-crackers crumbs. Stir until well blended.
Press crumbs into a buttered 9 by 13 inch baking pan.
Melt the chocolate chips and butterscotch in microwave for a total of 2 1/2 minutes on high stirring after each 30 seconds. Pour over crumb mixture.
Refrigerate until chocolate is set.
Remove and cut into bars. Store at room temperature.