I dont' know what the cake is called but its not topsy turvy. I've seen a couple pics. Each cake is sitting on top of each other but half the cake is hanging in the air nothing under it and the next cake is hanging off the other side in the air. Don't have a clue how to construct a cake like that.
lots of dowels, then a center dowel.
The ones that I've seen with this design were dummies.