In a sealable bag, add the cookies or crackers you are using for the topping and crush using a rolling pin. Be sure to crush until the mixture is fine like sand, as any unbroken pieces will not color well.
Begin by adding 2-3 drops of the green food gel to the bag and shaking to coat and mix. Continue to add until you've reached the desired depth of color. (Mine took at least ½ a tube of gel coloring).
Spread a thin, even layer of buttercream onto each chilled cheesecake, and roll each iced cake into the bag of green "moss" topping, patting it in to secure it in place.
Top with a mini chocolate Easter bunny or chocolate eggs. Enjoy immediately.