Prepare cookie dough. Roll out dough and cut cookies using Maple Leaf Cutter. Bake cookies and cool completely on cooling grid. Prepare color flow icing; tint portions red and yellow. Thin a portion of red icing to pouring consistency. Using tip 3, outline cookies using full-strength red icing; let set. Using thinned red icing in cut parchment bag, fill in cookies. Immediately pipe tip 2 outline veins in thinned golden yellow icing. Let dry.