Thoroughly mix the tempura flour and brown sugar together.
Add a beaten egg to the mixture from Step and mix well. If it's hard to mix with a spoon, mix it with your hands. It's quite a heavy batter.
Once mixed, cut the sweet potato into 5 mm cubes and add it to the mixture together with the vegetable oil. Mix everything together thoroughly.
Wet your hands with water and roll the batter into balls before frying on a medium heat for roughly 8 minutes. Make sure to keep the balls under 3 cm diameter or you will have trouble cooking them all the way through.
These are the finished donuts, they kind of looked like balls of minced meat.
Story Behind this Recipe
I often make simple donuts out of tempura flour, but it's sweet potato season right now so I decided to make these this time.
The batter will be really thick so you will probably find it hard to mix. You might find it a bit messy but I tend to mix these donuts with my hands. These donuts contain brown sugar and will burn quite easily, which is why it's important to keep them under 3 cm in diameter. If they're too big the outsides will burn before they cook through to the middle.