optional: non-stick cooking spray or parchment paper
Instructions
Add butter chunks and 8 cups of marshmallows to a large microwave safe bowl. Microwave on high power for 2 minutes.
Remove from microwave quickly and stir until the marshmallows are no longer chunky and the butter is fully incorporated.*
Pour the remaining 2 cups of mini marshmallows and 5 cups Lucky Charms into the bowl of melted marshmallows and gently fold together until the cereal is fully coated.
Pour the marshmallow/cereal mixture into a lined or non-stick sprayed 9x13" pan gently spread the mixture so it is evenly distributed. Do not press it down too much or your treats will end up dense and hard when they set.
Sprinkle the remaining cup of Lucky Charms over the top and lightly press to ensure it sticks to the top. Allow to set at room temperature for about an hour before slicing into 12 squares.
Notes
*Alternately, you can add the marshmallows and butter to a large pot on the stove top and heat on low, stirring constantly, until the mixture is heated and melted together. Calories are automatically generated. For best results calculate based on your exact ingredients.