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

Preheat oven to 350 degrees (325 degrees for glass dish). In 13 x 9 inch baking pan, melt butter in oven. Sprinkle crumbs over butter; pour condensed milk over crumbs. Top with chips; press down firmly. Bake for 25-30 minutes or until lightly browned. Cool. Cut into bars.