1. Purple sweet potato peeled and thinly sliced
2. Steam on the pot for 20min
3. Then take out the steamed purple sweet potato and crush it into puree with a spoon
4. Then pour the mud into a clean bowl and add 4 yeast powder, 50g of white sugar and stir
5. Then cover with plastic wrap to proof
6. Proof until it is twice as large as there is a honeycomb shape inside, and then use chopsticks to stir and exhaust
7. Prepare a clean glass bowl and brush with cooking oil, then pour in the proofing batter and smooth it
8. Add your favorite raisins and black sesame seeds, then put it on the pot and steam for 25 minutes, turn off the heat and simmer for 5 minutes, then you can put it in the pot.
Purple sweet potato does not have a lot of moisture, so after adding flour, the amount of water can be determined according to the flour and it will be a paste.