I just came across this on the internet. Icould not get the video to run but it sounds interesting. Has anyone seen this or tired it? http://www.eater.com/2016/4/9/11393762/how-to-bake-a-graphic-print-into-the-side-of-your-cake
Yes. In culinary school it was known as Pate decor. The decorative sponge was baked separately and used to line the pan as described in the video, or simply wrapped around a cake.