Put butter in 8 inch square micro proof baking dish. Cook on Hi for 1 minute or until melted. Stir in crumbs and sugar; mix. Pat mixture firmly and evenly in bottom of dish. Cook on HI for 2 minutes. Cool partially. Mix coconut, milk and nuts. Spoon carefully over graham cracker crust. Cook on HI for 3 minutes. Rotate dish one half turn once during cooking. Sprinkle with chocolate bits. Cook on HI for 1 minute. Spread melted chocolate evenly over coconut mixture. Cool and cut into squares. Yield: 16 to 20 squares