2 sticks butter, melted
1 c peanut butter
2 c. graham cracker crumbs
2 1/3 c. powdered sugar
12 oz. pkg milk chocolate chips

Mix all ingredients, except chips. Press into 9 x 13 pan. Melt chips in microwave, about 4 minutes at 50% power. Spread over top and chill. Cut into bars after 1/2 hour.