I made a tree with rolled cakes. This is easy to make if you have the cake to do it with.
The tree-shaped cake that I caught a glimpse of on TV was nice. So I experimented to make something similar.
There is cream around the edges as well, so I don't think you need so much on the inside. (One box of heavy cream might not be enough if you add in lots of cream filling.)
Enjoy Japanese food around the world.