Prepare the dough
Mix the flour, salt, and baking powder (if using) in the bowl of a stand mixer.
Attach a dough hook to the mixer and combine the dry ingredients by mixing on medium-low speed.
While the mixer is running, pour in the water and continue kneading the dough until the dough forms. (If there are still dry flour spots after mixing for 2 to 3 minutes, add a little water, 1 tablespoon at a time.)
Transfer the dough to a floured work surface and knead until it becomes a smooth dough.
Then divide it into 4 parts. Knead each piece by hand to remove air bubbles and form into a ball.
Add 1½ tablespoons oil to an 8″ nonstick cake pan or similar sized pan. Then place the dough in the pan and coat with a generous amount of oil to cover all surfaces.
Cover the pan with a lid and let the dough rest in the refrigerator for at least 30 minutes or overnight.
Prepare Thai Basil Mixture
During the last few minutes of the dough resting, prepare the Thai basil mixture.
Add flour, 5-spice powder, salt and sugar to the bowl with Thai basil leaves.
Then fill a small pot with half a glass of oil and turn on the fire.
Once the oil is heated to 350F, remove it from the heat and carefully pour it into the bowl of Thai basil.
Using a spatula, quickly stir the mixture until well combined. The basil will release its moisture and become slightly thick and wet within a few minutes. Divide
Combine Bing
Roll out the dough balls and pour any excess oil from the pan onto the work surface.
Working with one dough at a time, flatten it with your palm. Oil a rolling pin or your fingers and roll or stretch the dough into a thin rectangle (about 12″X7″).
Spread a generous amount of basil mixture on the dough you rolled out. Press gently to adhere.
Fold the dough into layers using the fan folding method, stopping when 1 inch of dough remains.
For this last part, instead of folding, bring the top layer and fold it as if you were closing an envelope. Press the dough gently to adhere to the fillings.
Now grab both ends and lift up, then tap the dough against the surface, stretching it to make it thinner (this is an optional step).
To finish, roll the dough into a roll and tuck one end under the dough. After resting for at least 15 minutes, move on to the rest of the dough.
cook bing
When ready, heat a cast iron or nonstick skillet with a thin layer of oil. Then lightly oil your fingers and the work surface.
Flatten the coil-like dough with your palm into a larger circular dough about 5″-6″ in diameter or 1cm thick.
Transfer the dough to the pan. Using your fingers, gently roll out the dough to flatten it.
Cover the pan with a lid and fry over medium-low heat until golden brown, about 2-3 minutes. Check occasionally and adjust the heat if necessary.
Open the lid and apply a coat of oil to the top of the bowl before turning it upside down. Then close the lid and cook for another 2-3 minutes until it turns golden.