Preheat the oven to 350°F (175°C).
In a medium bowl, combine the graham cracker crumbs and melted butter. Stir until the crumbs are evenly coated.
Press the graham cracker mixture firmly and evenly into the bottom of a 9×13-inch baking pan to form the crust.
Pour the sweetened condensed milk evenly over the crust.
Sprinkle the chocolate chips evenly over the sweetened condensed milk layer.
Sprinkle the shredded coconut evenly over the chocolate chips.
Sprinkle the chopped walnuts evenly over the coconut layer.
Bake in the preheated oven for 25 minutes, or until the edges are golden brown.
Remove from the oven and allow to cool completely in the pan on a wire rack.
Once cooled, cut into 24 bars and serve.