This is the cake we finally came up with for my daughters party.

This was the lunch tray from Pop Tates the Chocolate Shop/ Café in the comics
Cake is Devils food, covered with chocolate fudge icing.
The base icing is buttercream, with fondant on the sides, so that I could make the edge of the tray. The burger is all buttercream, except the cheese and the tomato, as my daughter does not like fondant.
The ketchup is left-over fondant.
Thanks for looking,
Karen

Great job. Good detail on the ketchup packet.

Thank you sweetbaker. My daughter was so surprised to see the ketchup packet!
Karen