I made this Thomas birthday cake using two box cake mixes. I baked two cakes: one in a standard loaf pan, the other in an 11 X 7 Pyrex baking dish. I then cut the finished cakes to various sizes to build the carcass of the cake. I kept a standard Thomas train close by to guide the decorating of this cake.
Using store bought frosting and Wilton dyes, I piped the icing onto the cake using a star tip. For the areas that need to be decorated in black, use chocolate frosting as a base and add the black coloring to the frosting. The wheels were Oreo cookies decorated with blue icing.
The cake was a huge hit with my three year old. son!