Empty the container of Cool Whip into a large bowl.
Add peppermint extract and stir well.
Add drops of food coloring until mixture is your desired color of green.
In an 8 x 8 or 9 x 9 pan, spoon a bit of the Cool Whip mixture to make a thin layer.
Top with a layer of chocolate graham crackers.
Repeat layers until all your Cool Whip is gone. Make sure to end with the Cool Whip on top.
In a large ziploc bag, place 10 Mint Milano cookies. Crush with a rolling pin.
Sprinkle on top of cake.
Cover and refrigerate at least 6 hours. Overnight is best.
Cut and serve with a fresh mint garnish.