Preheat the oven to 325.
Grease the pan. I used a 9x9 square pan.
Line the bottom of the pan with graham crackers.
Line the graham crackers with chocolate squares.
Pour some mini marshmallows over the chocolate.
Put another layer of graham crackers on top of the marshmallows.
Pour another layer of marshmallows on top.
Put in the oven for 15 minutes.
Take out and enjoy! Best if served soon after taking out of the oven.