Prepare baking sheets or a large flat surface by lining it with parchment paper or wax paper.
Add butter to a large pot and heat over medium low heat until fully melted.
Add the marshmallows to the pot and stir until fully melted and smooth.
Add the green food coloring to the melted marshmallows and stir until well combined.
Remove from heat and pour in the cornflakes stirring together until they are fully coated in the marshmallows.
Scoop cornflakes out in ¼ cup portions and drop them onto your prepared surface.
Lightly grease your hands with a small amount of nonstick cooking spray or vegetable oil and use them to form the cornflake cookies into wreaths, creating a hole in the center.
Decorate each with 3 red hot candies to look like holly berries.
Let cool completely and then store in an airtight container until ready to serve.