To assemble cookie cake, place reserved icing in piping bag fitted with round tip. Place one of the largest cookies on the bottom, and place a dot of icing in center of cookie as glue. Place a second large cookie on top. Continue the process, using the icing to “glue” the cookies together. For each cookie cake, use 3 large cookies on the bottom, followed by 2 medium-sized cookies and 2 small cookies on top. Place small dot of icing on top cookie, and place small piece of cotton candy on top for decoration. Repeat with remaining cookies to make 8 cookie cakes.