In a large saucepan, combine 4 cups of mini marshmallows and 3 tablespoons of butter. Heat over low, stirring constantly for about 5-7 minutes until the marshmallows are completely melted and the mixture is smooth and glossy.

Remove the saucepan from the heat and quickly add in 6 cups of Blueberry Cheerios. Gently fold the cereal into the melted marshmallow mixture until well-coated.

Transfer the mixture into a greased 9x13-inch baking pan. Press down firmly to create an even layer.

If using chocolate, melt 1 cup of chocolate in a microwave safe bowl. Once the bars are cool, cut them into squares and dip each square halfway into the melted chocolate.