
There have been beautifully decorated cakes at weddings for at least a hundred years (and the tradition probably goes back much longer). The 1926 edition of Mrs. Peterson’s Simplified Cooking cookbook included recipes for both Bride’s and Groom’s Cakes.
I never heard of Groom’s Cake until I saw it in the old cookbook. An online search showed that Groom’s Cake is still served at some weddings. There is regional variation in the popularity of Groom’s Cake, with it being more popular in Britain and the southern U.S. than in other regions.
In the hundred-year-old cookbook, the batter used to make the Bride’s Cake was white. The same basic batter was used for both cakes, but fruit, cocoa and spices were added to the Groom’s Cake batter. It also was smaller than the Bride’s Cake, though both were beautifully decorated.

The cakes in the pictures were beautiful, but since I had no need for wedding cakes, I didn’t try to replicate them. In case you are interested, here are the recipes in the old cookbook:

I had never heard of this either!
I’ve made one decorated wedding cake. I may or may not have a picture of it somewhere.