Prepare cookie template. Print candy corn (same as the watermelon) template, trace pattern onto card stock and cut out.
Prepare icing. Follow recipe to prepare buttercream Icing.
Bake cookies. Prepare cookie dough following recipe instructions. Roll dough to 1/8 in. thick. Place in freezer for 5 to 10 minutes. Using card stock template and paring knife, cut out cookies, bake and cool.
Assemble sugars. Fill three parchment bags, separately, with orange, yellow sanding sugar and white granulated sugar. Cut 1/2 in. off tip of each bag.
Decorate cookies. Using the candy corn template draw a horizontal line 1 in. from the pointed end, then draw another horizontal line 1 3/8 in. from the first line. This should leave you with a 3/4 in. stripe. Place a flat piece of parchment triangle over template. Starting at bottom of pattern, tap parchment bag to sprinkle sugars to cover parchment covered template in this order: yellow, orange and white. Use the spatula to level the sugars.
Spatula ice cookie smooth, place cookie iced side down onto sugars. Press down gently. Repeat.