Add marshmallows and stir frequently until it has melted completely.
Stir in the lucky charms.
Spray a 9×13 pan with non-stick spray.
Spoon the mixture into the pan and spread out. Spray a piece of parchment paper with a non-stick spray and use the paper to press the mixture into the pan.
Allow it to cool for an hour at room temperature or until hardened. Then cut into perfect sized pieces.
Notes
Do not store these treats in the refrigerator or it will cause them to dry out.
Store the leftovers in an airtight container at room temperature for up to 5 days.