1. Cook the sweet potato for a couple of minutes, until soft.
2. Mash the sweet potato until it becomes a puree.
3. Mix the puree with the oat flour until completely integrated.
4. Form balls with the dough, flatten them and make a hole in the center.
5. Crush the nuts a bit and add them on top of each donut as a topping.
6. Spray a little vegetable oil and take them to the air fryer for 15 minutes at 180ºC/350°F.
7. Check the cooking and, if necessary, leave them for a few more minutes.