Place cakes on cooling grid over waxed paper-covered cookie sheet. Heat yellow icing in microwave at defrost setting (30% power) for 20-30 seconds; stir. Repeat until consistency of icing will pour. Pour over cakes. Let set.
Outline and fill in chocolate-covered areas with tip 10 and brown icing. Smooth with spatula. Sprinkle with jimmies. Insert sticks into cakes for decoration only.