2 c. powdered sugar
2 c. graham cracker crumbs
1 c. chunky peanut butter
1/2 c. and 2 tbsp. butter
12 oz. chocolate chips, semi sweet

Combine all ingredients (except chocolate chips) in mixing bowl. Spread on 9 x 13 inch pan. Top with melted chocolate chips. Refrigerate for 2 hours. Let stand at room temperature for 20 minutes before cutting.