Directions

1. 1

   Grease an 8x8-inch baking pan with butter. Place the Rice Krispies cereal in a large bowl and set aside.

2. 2

   In a large saucepan over medium heat, melt 4 tablespoons of butter. Add the 10-ounce bag of mini marshmallows to the melted butter and stir constantly until the marshmallows are mostly melted and smooth.

3. 3

   Remove the saucepan from heat. Stir the 3/4 cup of dry yellow cake mix into the marshmallow mixture until fully combined and smooth.

4. 4

   Pour the marshmallow mixture over the Rice Krispies cereal in the bowl. Using a rubber spatula and your hands, stir vigorously until all the cereal is well coated and evenly distributed throughout the mixture.

5. 5

   Once the mixture has cooled slightly (after about 2-3 minutes), fold in 1/2 cup of rainbow sprinkles, stirring gently until evenly mixed throughout.

6. 6

   Transfer the entire mixture to the prepared 8x8-inch pan. Using a buttered spatula and your fingers, press the mixture firmly and evenly into the bottom of the pan.

7. 7

   Spread the 7.5-ounce jar of marshmallow Fluff evenly across the top of the Rice Krispie layer with a spatula or offset knife, smoothing it out as much as possible.

8. 8

   Sprinkle additional rainbow sprinkles generously over the Fluff layer for decoration.

9. 9

   Place the pan in the refrigerator for 20 minutes to allow the mixture and Fluff topping to set completely.

10. 10

    Remove from the refrigerator and cut into 25 squares using a sharp knife, wiping the blade between cuts for clean edges.

11. 11

    Serve at room temperature. Store any leftovers in an airtight container at room temperature for up to 3 days.