Preheat your oven to 350 degrees. Lightly grease a 9x13 inch baking dish with cooking spray. Finely chop the nuts into small bite-size pieces. Set aside.
In a medium bowl combine the graham cracker crumbs and melted butter. Using a wooden spoon, blend until a fine crumbly mixture forms. Transfer the graham cracker mixture to the baking dish.
Spread and press the graham cracker mixture into the bottom of the prepared baking dish to form a crust. Next, pour the sweetened condensed milk over the crust so that it covers the surface.
Begin layering by adding a layer of chocolate chips, then flaked coconut, and chopped nuts. Bake for 25 minutes or until the coconut is lightly toasted. Cool, and slice into bars. Or, chill in the refrigerator overnight for firmer bars.
If you're unable to find graham cracker crumbs at your local grocer, simply use whole graham crackers, and crush them yourself. One sleeve of crackers is equal to 1 1/2 cups of graham cracker crumbs.
Use a food processor or blender, then pulse in small bursts until you have fine crumbs. If you don't have a blender or processor handy, place the graham crackers in a heavy-duty plastic bag, and use a rolling pin to crush them.