1/2 lb. melted butter (2 sticks)
1 1/2 cups graham cracker crumbs
1 lb. powdered sugar (4 cups)
1 cup smooth peanut butter
12 ounce semi-sweet chocolate chips
Mix all except chocolate chips in 9×12 pan, by hand. Press in bottom of pan.
In microwave, melt 12 ounce of semi-sweet chocolate chips. Pour over crust; cool until set; cut into bars.
Norpro Professional 9-Inch by 12-Inch Heavy Gauge Cookie Sheet