01 -
Give a 9-by-5-inch loaf pan a light coat of cooking spray, then line it with two crisscrossed strips of parchment paper, letting the edges hang over the sides. Spray the parchment lightly as well.
02 -
In a microwave-safe bowl, combine 1½ cups of marshmallows and 1 tablespoon of butter. Heat them in the microwave for a minute, until the marshmallows puff up and the butter's melted. Stir until smooth. Add a few drops of food coloring and mix well. Toss in 1½ cups of cereal and coat everything evenly. Use sprayed hands or a spatula to press it into the pan in a flat layer.
03 -
Repeat the previous step three more times, using a new color for each batch. Flatten each layer into the pan evenly, pressing everything together firmly.
04 -
Pop the pan in the fridge for about 20 minutes, or until it's nice and firm.
05 -
Grab the parchment paper edges to lift the cereal block out of the pan. Peel off the paper, then slice the block into ¾- to 1-inch-thick pieces. Use an egg-shaped cutter (about 3 to 4 inches) to carve one egg shape diagonally from each slice.