1Preheat oven to 350 degrees F (175 degrees C). Butter a 9x13 inch baking dish.
2In a medium bowl, combine butter, sugar and graham cracker crumbs until well coated. Press half of crumb mixture into the bottom of the prepared pan. Top with the chocolate chips, then the marshmallows. Sprinkle the remaining graham cracker mixture over the marshmallows and press down with a spatula.
3Bake in preheated oven 10 minutes, until marshmallows are melted. Cool completely before cutting into squares.
Footnotes
Tip
Aluminum foil can be used to keep food moist, cook it evenly, and make clean-up easier.