Prepare the Pan: Grease a 9x13-inch baking dish with butter or non-stick cooking spray.
Melt the Butter: In a large pot, melt the stick of butter over low heat.
Add Marshmallows: Once the butter is melted, add 16 oz of mini marshmallows. Stir continuously until the marshmallows are completely melted and smooth.
Add Vanilla Extract: Stir in the ½ tsp of vanilla extract until well combined.
Combine Dry Ingredients: Remove the pot from heat. Quickly add the 7 cups of Rice Krispies cereal and 2 cups of broken graham crackers. Stir until the cereal and crackers are evenly coated with the marshmallow mixture.
Mix in Chocolate Chips and Extra Marshmallows: Add the 1 cup of semi-sweet chocolate chips and the 1 extra cup of mini marshmallows to the mixture. Stir until the chocolate chips and extra marshmallows are evenly distributed. (the chocolate chips will melt down a bit as your stir)
Press into Pan: Pour the mixture into the prepared baking dish. Use a greased spatula or wax paper to press the mixture evenly into the pan. Evenly top with the remaining mini marshmallows and chocolate chips.
Cool and Set: Let the treats cool completely in the pan at room temperature for about 1-2 hours.
Cut and Serve: Once cooled and set, cut the S'mores Rice Krispie treats into squares. Place one square at the end of a roasting stick and roast the rice krispie treat over a campfire until golden and warm. Be careful when eating, they can get very hot!