Combine oatmeal, brown sugar, flour, coconut, baking soda, and salt; add melted butter and stir until moist (the mixture will be crumbly). Reserve 1 1/2 cups and press remaining crumbs into a greased 13X9-inch baking pan (I line the pan with non-stick foil.).
Bake 12 minutes at 375°F.
Combine milk and peanut butter; carefully spread over baked crust. Sprinkle on M&M's and chocolate chips. Sprinkle reserved crumbs over chocolate pieces and lightly press crumbs down.
Bake 20 minutes, or until golden brown. Cool completely before cutting.