Place the butter and marshmallows in a microwave-safe bowl. Microwave in 1-minute intervals, stirring after each interval, until marshmallows and butter are completely melted, about 3 minutes total. Stir a small amount of food coloring into the mixture.

Measure the cereal into a very large mixing bowl. Working quickly before it starts to set up, stir the marshmallow mixture into your cereal.

Spread the mixture into a greased 9x9" pan. Allow to cool completely. (To speed up cooling time, place the pan in the fridge for 15-20 minutes.) When the mixture has cooled, use a Christmas tree cookie cutter to cut tree shapes.

Melt 1/2 cup of the white candy coating pieces according to the package instructions. To assemble each pop, dip the ends of a lollipop stick into the melted candy coating, and then carefully guide it through the end of one of the trees. Decorate the trees with white frosting and M&M's, using the frosting as the "glue" to hold the candy in place.