S'mores Rice Krispy Treats

Grease 9x13 baking dish and set aside. Set aside 1 cup marshmallows. In a large saucepan over medium heat, melt butter. Add remaining marshmallows and stir over heat until they begin to lose their shape. Remove from heat and add cereal and graham crackers. Add reserved cup of marshmallows and chocolate chips and stir quickly so they don't melt. Pour and press into prepared pan. Cool and cut into pieces.