I made this Transformers Optimus Prime cake awhile ago. I couldn’t really find any good ideas to copy from the internet (although there was one amazing freestanding Optimus Prime that did inspire me but was going to be way to hard to replicate) so I just made one up myself. Anyway this was not necessarily hard but quite time consuming.
The cake was a butter cake and I used rollettes for the round pieces. Most of the cake is iced with coloured butter icing except for the silver icing which was the roll out icing that I painted silver with paint on food colouring (comes in a container that makes it look rather like nailpolish!)and the yellow icing which was also roll out icing. Oreos make good wheels.
I made sure all the cake was frozen when I iced it which made it a lot easier. I used skewers and tooth picks to hold it together.