Combine the flour, yeast, baking powder, sugar, and salt in the bowl of a stand mixer. Slowly pour in the milk while using a spoon or spatula to mix with the flour. Once the liquid is fully combined, turn on the mixer and knead for 5 minutes until it forms a firm and coarse dough ball. Alternatively, you can use your hands to knead the dough and it should take about 10 minutes.

Cover the bowl with plastic wrap and let the dough rest for 10 minutes.

After 10 minutes, knead the dough using your hands, for another minute, until smooth. Cover with plastic wrap. Rest the dough until it doubles in size, about 1 hour.

While the dough is rising, prepare 10 pieces of square parchment paper about the size of your palm, to hold the buns while steaming.

(Optional) If you’re making the gua bao filling and quick pickled shallots on the same day, prepare them during this time.

Once the dough has doubled in size, punch the dough gently with your hand to release the air bubbles. Knead for 1 minute.

Cut the dough into 2 equal pieces, then further divide each piece into 5 smaller pieces. For a more accurate result, use a scale to measure the dough to make sure it’s 48 g per piece.

Work on the dough pieces one at a time, forming them into balls by pinching the loose ends into the base until taut and round. Then roll the dough on the table using your hand shaped like a dome, lightly pressing the dough so it forms a round ball. Place the dough balls on a large plate and cover them with plastic wrap to prevent them from drying out.

Place the dough balls pinched side down onto a clean working surface. Using a rolling pin, roll each ball into a 1/4" (1/2 cm) thick oval that's twice as long as it is wide (about 2.25” x 4.5”/ 5.5 cm X 11 cm). Flip the dough oval over and lightly roll again to smooth it out,

Brush the top of the dough oval with a thin layer of oil (*Footnote 1), fold the oval in half, and place it on a piece of parchment paper you prepared earlier.

Place the shaped buns in a steamer basket, leaving at least 1” (2.5 cm) between the buns. Cover and let rise for another 15 to 30 minutes before cooking, or until the size is 1.5 times bigger.

Right after you finish forming the first batch of buns, prepare the steamer by adding water into the base. When the buns have risen the 2nd time, add the covered steamer rack with the risen buns over the steamer. If using a metal steamer, use two layers of clean kitchen towels between the steamer rack and the lid to prevent water from dripping. Cook covered over medium heat until steam starts coming out of the pot, then turn to medium-low heat. Steam for another 10 minutes.

After 10 minutes, turn the heat off but leave the lid on for another 5 minutes. Do not open the lid at this time! The buns might deflate without the proper resting.

Once done, remove the buns onto a wire rack to cool. Then you can use the same steamer to cook the rest of your buns.

You probably will need to cook the buns in batches depending on the size of your steamer. While you’re steaming the first batch of the buns, the second batch or the third batch might have been formed and rested. In this case, transfer the buns onto a big plate and cover them with plastic wrap. Transfer the buns into the fridge to slow down the rising. Wait until the previous batch of buns is done. Remove the rested buns from the fridge, let them return to room temperature for 2 minutes, then start steaming them. It’s important to NOT allow the buns to rise too much. If the buns are rested for too long, they will deflate once steamed.

Once the buns are steamed and slightly cooled, you can use them to make gua bao, serve them with moo shu chicken, or stuff them with any braised meat.

You can store the steamed buns in an airtight container in the fridge for up to 4 days, or in a tightly sealed ziplock bag in the freezer for up to 3 months.

To reheat the refrigerated buns, you can place the buns on a plate and cover them with a layer of wet paper towels, then heat them up in the microwave. You can also heat the buns in a steamer, which will create a softer result.

To reheat the frozen buns, place them directly in a steamer without thawing them and steam until fully heated through. If you want to reheat them in the microwave, you should thaw the buns first.