Into large bowl, measure cereal. Butter 14x10-inch pan. In large microwavable bowl, microwave marshmallows and butter uncovered on High, 30 seconds at a time stirring after every 30 seconds, until melted and smooth when stirred.
Pour over cereal; quickly toss until completely coated.
Press mixture evenly in pan, using buttered back of spoon, or buttered hands. Let stand uncovered at least 1 hour, or refrigerate if you prefer a firmer bar. For bars, cut into 8 rows by 10 rows. Store loosely covered at room temperature up to 2 days.
Makes 80 small treats.
Servings 0