1/2 c. butter
1 1/2 c. graham cracker crumbs
1 (14 oz.) can sweetened condensed milk
1 (12 oz.) pkg. chocolate chips (semi-sweet)
1 c. peanut butter chips

Preheat oven to 350 degrees (325 degrees for glass dish). In 13x9 inch baking dish, melt butter. Sprinkle crumbs evenly over butter; pour sweetened condensed milk evenly over crumbs. Top with chips; press down firmly. Bake 25 to 30 minutes or until lightly browned. Cool.