Cake decorating is one of the sugar arts that uses icing or frosting and other edible decorative elements 
Sugar arts? that sounds amazing haha. How long have people been decorating cakes?
Interestingly,It originated in 17th century Europe.
I wonder what they used to apply frosting and that sort of things back in the 17th century
In 1840s, the advent of temperature-controlled ovens and the production of baking powder made baking cakes much easier.