Make box brownie mix according to it's directions and add 1/2 cup chocolate chips into the mix. Bake 3-5 minutes less than what the box says. While baking, crush graham crackers in a gallon sized plastic bag with a rolling pin. Mix crushed graham crackers with melted butter.
Take brownies out of the oven with a few minutes left and still a little gooey. Sprinkle with remaining chocolate chips and then cover with a good amount of graham crackers.
Top with marshmallows and place back into the oven for the remaining 3-5 minutes until marshmallows start turning golden brown. Remove from oven, top with more graham crackers if desired, and allow to cool for 30 minutes before slicing.