Add 2 cups of corn flakes to a large bowl. With your hands, gently crush the corn flakes into smaller pieces. Add the other 2 cups of corn flakes and gently mix them all to combine.
Melt the butter in a medium-sized saucepan over medium heat and add the marshmallows. Stir to melt and add 10-15 drops of green food coloring and mix well to combine. Add more food coloring for a deeper green color.
Once marshmallows are all well melted and combined, pour it all into the large bowl with the corn flakes. Mix well until all of the corn flakes are well combined.
Spray a spoon or your hands with some cooking spray or oil and scoop out small palm-sized rounds of corn flakes and place them onto parchment paper. Add green sprinkles and green and red mini M&Ms. Repeat with all cornflakes.
Let cool for at least 15 minutes before removing from parchment paper.
Store in an airtight container for 3-4 days on the counter or up to 2 months in the freezer.
Notes
StorageStore in an airtight container on the counter for 3-4 days. Tip: grease your container to prevent sticking, and use either parchment or wax paper to separate layers of cookies. Freeze for up to 2 months.Shaping/Decorating TipsYou will want to work fast to be able to get the M&Ms to stick while the cookies are still tacky. This is great to do with kids so they can decorate right after cookies are placed on parchment. But if doing alone, you can keep the "dough" warm and sticky by placing the bowl over a pot of hot water. This will help keep the marshmallows sticky and pliable. SubstitutionsMarshmallows: Large or mini work fine. Butter: Unsalted is fine too - just add a lil pinch of table salt to the marshmallows while they melt. Corn flakes: Use your favorite, or even bran flakes if you'd like. Decorations: Use red hot candies or any other favorite decorative red and green candies!