I ordered a cake for my mom's birthday--and it was not very good. It was covered in what was supposed to be buttercream, but which bore no resemblance to any buttercream I have ever made or tasted. It was much more like Crisco whipped with powdered sugar. I could not detect any flavor of butter at all. Was this "buttercream" or "buttercreme"? Are there any rules about what can and cannot be called "buttercream?"