Mix together and press into 9 x 13 pan:

3 1/2 c. powdered sugar
1 1/2 c. graham cracker crumbs
2 sticks butter, melted
1 c. peanut butter

Melt together (microwve is great!) 12 oz. chocolate chips and 1/2 c. peanut butter. Spread on crust and chill. Cut into squares.