1-1/2 cups mixed berries, such as strawberries, blueberries and raspberries
Microwave butter in large microwaveable bowl on HIGH 30 sec. or until melted. Add marshmallows; toss to coat. Microwave 1-1/2 min. or until marshmallows are completely melted, stirring after 45 sec. Add cereal; mix well.
Press firmly onto bottoms and up sides of 12 lightly greased medium muffin cups; cool.
Fill each with 2 Tbsp. whipped topping; top evenly with berries.