1.Preheat oven to 350 (or to directions on brownie mix).
2.In a 9×9 pan, melt butter. Add graham cracker crumbs, making sure they are fully moistened and press into a sturdy crust.
3.Mix up brownies, and pour batter over crust. Bake for recommended time on box. Test with a toothpick before removing – the brownies likely need another 15-20 minutes because of the graham crust on the bottom.
4.Once fully finished baking, add on jumbo marshmallows. Set under the broiler for 1-2 minutes, or back into the preheated oven for about 10 minutes. Watch closely to make sure marshmallows don’t burn.
5.Let cool completely – 2-3 hours.