I used the Barney Wilton pan (discontinued) for this. My almost 2 year old girl insisted for weeks she wanted B.J, not Barney or Baby Bop. I found the pan at a local small cake store after gasping at the Ebay prices. This was the first cake I ever made with a tip. :)
Basically I baked the cake in the pan & then frosted it as seen using a coloring book picture that was at this angle. Unfortunately, I did not know that store frosting was not good for stars so this was the result. As it warmed I would put it back in the fridge for 10 minutes or so & use a different color meanwhile.