Steam or boil the sweet potato, peel, and mash it.
In a bowl, mix the mashed sweet potato, Greek yogurt, honey, and egg well.
Add oat flour and baking powder, mix evenly.
Pour the batter into a mold.
Bake in a preheated oven at 180°C for 25 minutes.
After cooling, top with nuts, extra yogurt, or honey as desired.