In a sauce pan, turn the oven to medium-low heat and add the butter and marshmallows to the pan. Let the butter and marshmallows start to melt over the heat. Keep the temperature not too hot, so the marshmallows don't burn. Let them cook for a few minutes while you prepare the rest of the recipe by pouring the chocolate chips and the Golden Grahams into a large mixing bowl. Remove the marshmallow mixture from the stove and pour over the cereal. Stir until it's all combined. Spray a 9x13 pan and pour the cereal into the glass pan. Spread the mixture evenly into the pan. Let the bars cool completely and then cut into squares to serve.