1) Preheat oven to 325 degrees

2) In a large bowl, combine the graham cracker crumbs with the melted butter. Press firmly into an ungreased 12 x 18" jelly roll pan

3) Sprinkle the walnuts, chocolate chips, and shredded coconut over the graham cracker crust

4) Pour the three cans of condensed milk over everything evenly, making sure to completely cover the coconut. Use a spatula to spread if needed

5) Bake for 30-35 minutes, or until lightly golden

6) Cool to room temperature, or overnight, before cutting and serving