Use your favorite white colored store bought frosting, or your favorite homemade frosting recipe and add your favorite color to make these spooky treats. I like separating the frosting into multiple bowls to make a few colors for the cookies. Color the frosting with food coloring in whatever colors you like that seem extra fun for these festive treats. I like purple, green, and orange icing, but red, or black, or yellow, etc. would be great.