I have seen on cake shows/challenges people using cake for stacking ect. And im wondering what kind of cake is being used? It seems to be very dense and sturdy for carving and stacking and very little crumbs.
For carved and stacked cakes I use a dense pound cake. My dog cake had no cardboard rounds between layers or rice krispie treats, just a dowel down the center and a few straws for the legs and nose -- it was all cake and about 18" tall. I also drove it 40 miles across town.
I used scratch pound cake for my TLC cake. held up great, even after being shipped.
I don't do carved cakes, but for pretty much all of my cakes, including stacked cakes, I make butter cake.