Preheat oven to 350° (325 for glass)

Melt the butter in a 9x13 dish.

Sprinkle graham cracker crumbs over the butter and mix well.

Pour some of the sweetened condensed milk on top of the graham cracker crumbs. Then put all the chocolate chips in a layer on top of the sweetened condensed milk and pour the remaining sweetened condensed milk on top of the chocolate chips.

Pour the coconut on top of the chocolate chip and sweetened condensed milk mix.

Put the walnuts on top if you would like walnuts.

Bake for 25-30 minutes.