Preheat oven to 350 degrees C.
Melt butter and in a bowl and combine it with the graham cracker crumbs until evenly mixed.
Using your hands, press this mixture into an even layer on the bottom of a 9 x 13 dish.
Spread coconut evenly over the graham layer.
Roughly chop the walnuts and spread evenly on top.
Spread the chocolate mixture evenly on top of that.
Drizzle the sweetened condensed milk over the whole thing.
Bake in the oven for 30 minutes. Allow to cool completely, you can place it into the fridge too for a couple of hours which makes for easier cutting. Cut into 15 bars. Enjoy!