Using 2 broad spatulas, flip other cake, flat side up, to another corner of the tray. Cutting 2 in. Spoon out center to form a shallow bowl. Spread inside of bowl and the 2-in. Scatter red and black licorice bites in bowl as coals.
Place cookies on grill.
Snip a tiny corner from bag with mustard. Squirt on hamburgers and hot dogs. Squirt red gel for ketchup. Squirt triangles of red gel on tomato slices. Use tip of a toothpick to pick up and drop sesame seeds in place for tomato seeds.