Step 1

Grease a 9 x 13 inch baking dish with non-stick cooking spray or line with non-stick foil. Set aside

Step 2

In a large, microwave-safe bowl, place the marshmallows and butter. Microwave for 1 minute. Stir, and microwave for an additional minute. Be sure to watch the microwave so the mixture does not puff up too high and spill. If needed, microwave for an additional 30 seconds. Mixture should be very smooth.

Step 3

Alternatively, melt the marshmallows in a saucepan over medium-low heat, stirring frequently.

Step 4

If desired, stir in cocoa powder.

Step 5

Scrape the mixture into a large bowl with the cereal. Fold the mixture with the cereal to completely coat the cereal.

Step 6

Transfer the mixture into the prepared baking dish, using a clean spatula to press the cereal treats evenly in the dish.

Step 7

Let cool completely about 2 hours. Cut into 2-inch square.