This is a some sort of buttercream/custard. It calls for whole egg cooked over a double boiler with chocolate and sugar until it thickens and then when it cools, you add softened butter. It's pretty hard to pipe with as it warms quickly, but the taste?!?!?!

The only "boo-boo" was that I had someone take a picture at the event and it had already been smudged on top by a curious finger! LOL, but unitl then it looked pretty good. Cake is a walnut cake - no flour.