Edubuntu was the first Ubuntu distro to have a cake (thanks to Jane Weideman) in October 2005:
Recently, the other Ubuntu distributions followed suite:
The Edubuntu cake is the biggest so far, while the Kubuntu cake is at least 40% more blue than the other cakes. The Ubuntu cake happened to be a birthday cake (nice, eh?).
We haven’t seen any reports of a Xubuntu cake yet, although spy reports claim that another cake will emerge within the next 30 days. Stay tuned…