Processing :

1. Prepare tray and fryer.
2. Separately weigh ingredients.
3. Add all ingredients into mixing bowl except butter.
   3.1. Mix at slow speed about 3 min for well cooperating all ingredient.
   3.2. Switch to fast speed til the dough surface is smooth then add butter and mix til dough is completely developed (thin film dough).
   Round the dough and rest 10 min.
4. Dust a bit flour on table; use rolling pin roll the dough to 25cm x 50cm rectangle. When reach to proper size, pick it up, use dry brush to sweep off any excess flour and fold the dough in thirds.
5. After that, let the dough rest for 10 - 15 min.
6. Roll the dough out until thickness is 8mm.
7. Use donut cutter to cut dough.
8. Proof at 35 degree C around 90 min.
9. Fry at 180 degree C for 2 min til get golden brown color evenly for 2 side of donut.
10. Take the donut out, cool down and enjoy.