Prepare an 8 or 9-inch square baking pan with wax paper. Spray the top of the paper with non-stick cooking spray.

Add the marshmallows and butter to a large microwave-safe bowl.

Heat in the microwave for 1 minute and then stir. Heat for another minute and stir it again. Repeat this until the melted butter and marshmallow mixture is smooth.

Divide the melted marshmallow mixture between six different bowls. Add enough gel food coloring to each until you get the desired color you’re looking for. Stir well to combine.

Fold 2 ½ cups of cereal into each bowl, until it’s coated in the marshmallow mixture.

Press the mixture into the prepared baking sheet in even layers using a buttered spatula. You’ll have thin layers of each color; red, orange, yellow, green, blue, purple.

Keep layering until you have all the layers pressed firmly together. Keep the square shape as you stack the layers. Then cool completely.

Lift the layered square from the baking dish using the waxed paper and place it on a cutting board. Trim up any uneven edges if you need to.

Cut the square in half and then slice each half in servings, approximately 1-inch thick.