Melt margarine or butter in large saucepan over low heat. Add marshmallows and stir constantly until completely melted. Remove from heat. Add cereal and stir until well coated. Using buttered spatula or waxed evenly into greased 13" x 9" pan. Cut into square when cool.
Microwave Directions: In microwave-safe bowl, microwave margarine or butter and marshmallows on HIGH for 2 minutes. Stir to combine. Microwave on HIGH for 1 minute longer, stir until smooth. Add cereal and stir until well coated; continue as directed above.