- Stir boiling water into gelatin in medium bowl at least 2 minutes until completely dissolved. Stir in cold water and ice cubes to make 1 cup. Place in refrigerator 15 minutes or until slightly thickened.
- Puree bananas in blender (1 cup).
- Combine yogurt and pureed bananas in large bowl. Stir gelatin mixture into banana mixture. Fold 2 cups whipped topping into gelatin mixture with sliced strawberries.
- Spoon gelatin mixture into 2 qt. (11 x 7-inch) shallow baking dish. Refrigerate until firm.
- Spread remaining 2 cups whipped topping over filling. Arrange additional strawberry slices on whipped topping for flag stripes. Arrange blueberries on whipped topping for stars.