Combine together the butter, brown sugar and basic sugar until mixed well.
Add the eggs, flour, baking soda, and creme de menthe liqueur.
Place 8-10 drops of green food coloring and continuing to mix well. This will give the dough a lovely pop of green coloring. Add more or less depending on the deepness of the hue you are trying to achieve.
Drop spoonfuls of the mixture onto a greased cookie sheet, placing each spoonful about 2 inches apart.
Bake for 8 to 10 minutes. Allow cookies to cool before removing.
Once the cookies are cooled, spread a generous amount of vanilla frosting (you may color this green too if you wish, however we left ours plain white for a nice contrast) onto the center of the cookie.
Top the frosting with another cookie and press together gently.
Finally, sprinkle some green sugar sprinkles onto the frosting or roll the sides of the cookie cakes into the sprinkles.
Recipe by Crazy About My Baybah at http://www.crazyaboutmybaybah.com/creme-de-menthe-cookie-cakes-st-patricks-day-cookies/