Oh of course it would not be a very nice cake, but they are aliens and are pretty new to food in general so yeah they are going to screw up a bit.
And yeah motor oil is definitely the final straw that makes the cake inedible, which they didn't know with their limited knowledge of Earth.
When I made their messed up recipe to get pictures I didn't go that far - I stopped at the mix - but making it did mean I needed to clean my kitchen afterwards too after smashing eggs on the floor and island bench for the sake of pictures too - it did make me give it a good mop though and it was probably about due for it- so I guess that's a win?
Thanks for you comment. I'm glad you found it funny.