Preheat oven to 350°F (325°F for glass pan). In a bowl combine butter and cookie crumbs; press mixture into the bottom of a 13x9 inch baking pan. Pour sweetened condensed milk evenly over the crumbs. Combine the M&M' Baking Bits, coconut, and nuts. Sprinkle mixture evenly over condensed milk; press in lightly. Bake 25 to 30 minutes or until set. Cool completely before cutting. Store in tightly covered container. Yield: 32 bars