Dough with potato is impressively soft. This is sweet potato, and the dough is kept high hydration as well. That means the dough is very sticky and wet.
You notice how boxed cakes call for adding vegetable oil instead of butter. This has vegetable oil as well along with generous butter spread over it. Vegetable oil in the dough, butter on the dough. The icing also has butter.
The filling has fresh pineapple that was frozen in chunks and chopped up further for this. I wish I had thought of pecans but it didn't occur to me at the critical moment.
* confectioner's sugar
* Philadelphia cream cheese
* pinch of salt