Congratulation Cake

Who don't like a cake ? A cake with a picture of your car, that's even better ! Size doesn't matter here but the content is more important. Above is a cake with a picture of HT81S on the top. I wonder how they do it ? Printing ? Is it edible ?
The note on the top are for 19 years celebration. Anyway, I too wish Omedeto to the owner.
Photo taken from twitter and credit to the owner.