Melt the butter in a large pot.
Add the marshmallows to the pot and coat with the melted butter. Stir continuously until marshmallows are completely melted.
Turn off the heat and add the Malt-O-Meal® Berry Colossal Crunch® cereal. Mix thoroughly with the melted marshmallows and pour into a greased 8”x8” glass pan.
Pack the treats tightly in the pan and let cool completely. Cut out the crispy treat servings and enjoy!