In a large saucepan, melt the butter and marshmallows. Stir frequently until you have a smooth mixture.
Turn off heat and add the vanilla and green food coloring. Stir until blended. Don't worry that the mixture is too green - it will be!
Stir in the corn flakes until all are coated. Use a folding motion so you don't smash the corn flakes too much.
Using 2 teaspoons, drop a heaping teaspoon of the mixture onto waxed paper sprinkled with powdered sugar. (I use a sifter to get the sugar onto the paper lightly, since you don't need a lot of the powdered sugar, just a light dusting.)
Work quickly so the mixture doesn't set up, which makes it hard to get them out of the pan. This recipe can be doubled, but I would recommend you try a single recipe first so you can see how they tend to start setting up.
After all the holly wreaths are out on the waxed paper, add 1-2 cinnamon decors to simulate the holly berries. (I recommend leaving off the cinnamon candies for small children).
Let the wreaths sit for about 1-2 hours to dry a bit. Then store in a container on waxed paper. You can make several layers in your container.
Hint: if the bottom of the wreath seems too sticky after letting them sit, then lift them off the waxed paper with a spatula and dip the bottom into more powdered sugar before you store them.