1. Pour milk and add sugar into the Bosch mixer or a mixer.
2. Next, add active dry yeast.
3. Turn on the Bosch mixer, the lowest setting #1, let it mix a little bit, cover the lid and wait for 5 minutes.
4. Meanwhile, put bread flour into the container. Then, add salt. Mix them well.
5. The following, turn on the Bosch mixer the lowest speed #1, slowly add the flour mixture from step 4 into the yeast mixture in step 3. Then, change the speed to medium #2 or 3.
6. While the dough is mixing, cut unsalted butter into small cubes. Then, add the butter into the dough one at a time. Let the Bosch mixer run for 10-15 minutes until the dough is not too sticky.
7. After that, put the dough into a mixing bowl and cover with a wet cloth. Let it rise for 45 minutes to an hour at room temperature.
8. While waiting for the dough, put a parchment paper into the pan (9.5 inches square pan) and spray some oil.
9. After the dough rises double size, roughly divide the dough into 12 pieces.
10. Roll the dough into a ball and put it on the pan.
11. Cover the dough rolls with a wet towel and wait 15-30 minutes at room temperature.
12. Put bread flour into a strainer and dust the flour over the dough.
13. Preheat the oven at 350F, then drop the temperature and bake them at 300F for 18-22 minutes.