Rice Krispie Treats

3 Tbsp margarine or butter

1 10oz pk regular marshmallows

or

4 cups mini marshmallows

6 cups Rice Krispies

Melt margarine in large saucepan over low heat. Add marshmallows and stir until completely melted. Remove from heat. Add cereal, stir until well coated.  Using buttered spatula or waxed paper, press mixture evenly into 13 x 9 pan coated with cooking spray.  Best if served same day.