I participated in the cake class at Charm City Cakes offered the Thursday before BronyCon. It was /amazing/ to say the least. Everyone was marvelously nice, and I got to take a cake decorating class at last.
They even let us make the cakes sparkly, using the awesome airbrush setup!
I made a Pinkie Pie themed cake, and the insides were actually pink! It is white cake colored that way - but it is quite tasty!