A 7 oz. jar of marshmallow creme can be substituted for a 10 oz. bag of marshmallows. Melt 3-4 tablespoons of margarine or butter in a large saucepan, add the entire jar of creme, still well, remove from heat, add to six cups of cereal, stir until well coated. Then, using a buttered spatula or wax paper that has been sprayed with Pam, press mixture evenly into 13 x 9 x 2-inch pan coated with cooking spray. Don't cover the pan until the mixture is thoroughly cool and even then, I prefer to just lay a piece of wax paper on top. This keeps the Rice Krispies from becoming tough.