How come I didn't know this quick method before? Stay soft and fluffy- 3 days. Homemade Donuts

Hello everyone this time I made a favorite food. Quick recipe with 1 time of proofing. I use a simple tool to knead the dough.

Donuts "All In One" method one proofing only.
Source: "Papa's Recipe"
Re-cooked: "Vinastar Channel"

250 grams of flour for bread.
15 grams of powdered milk.
35 grams of sugar.
1 tsp instant yeast.
1/2 tsp salt
1/3 tsp "bread improver" (optional)
30 grams of butter or margarine