In your stand mixer bowl, combine the lukewarm water, dry instant yeast, and sugar. Stir gently with a small whisk until the granules are completely dissolved.

Add the 300g of bread flour, 6g of baking powder, and 6g of salt directly into the liquid. Mix with a spatula or your mixer on low speed just until a cohesive, shaggy mass forms and no dry flour patches remain.

Cover the bowl and let the mixture rest undisturbed for 30 minutes for the autolyse phase. During this time, the flour fully absorbs the moisture, which naturally jumpstarts gluten alignment. The dough will look lumpy, but it will smooth out perfectly during kneading.

After the autolyse rest, pour the 15g of oil over the dough. Knead by hand or with your mixer on medium speed for 5 to 7 minutes until the oil is completely incorporated and the dough turns smoother and more elastic.

Cover the container tightly and let the dough rise at a warm room temperature for 1 hour to 1 hour and 30 minutes. Perform one clean stretch-and-fold session during this bulk rise. The finished dough should grow to nearly double its original volume.

Lightly sprinkle your clean counter surface with flour. Turn out the puffy dough and roll it out with a rolling pin until it reaches a uniform thickness of 1/4-inch.

Using a sharp round cookie cutter or the rim of a wide wine glass, cut out clean circles from the sheeted dough. Gather any remaining scraps, knead them together briefly, roll them back out, and cut out additional circles until you have exactly 12 rounds.

Use your rolling pin to gently roll each individual circle out slightly along one axis to create an elongated, oval shape.

Dip a pastry brush into your extra neutral oil and spread a light layer across the top surface of each dough oval.

Fold each oval cleanly in half to form a classic half-moon pocket shape. The thin layer of brushed oil prevents the two halves from fusing back together while steaming.

Transfer each folded bao bun onto an individual small square of parchment paper. Cover them loosely and allow them to proof undisturbed on your counter for exactly 30 minutes.

While the buns are proofing, fill your wok or steamer pot with water and bring it to a rolling boil over high heat on your stovetop.

Arrange the proofed buns (leaving their parchment squares underneath) inside your bamboo steamer basket, leaving plenty of space between them to allow for steam expansion.

Carefully position the steamer basket directly on top of the boiling water pot. Ensure that the water level is low enough that it never comes into direct contact with the bottom of the buns.

Cover tightly with the lid and steam over medium-high heat for exactly 2 to 3 minutes.

Once the cooking time concludes, turn off the heat but do not open the lid immediately. Tilt the lid open just a tiny fraction of an inch to let a small amount of cool air circulate slowly for 2 to 3 minutes. This gradual temperature shift prevents the delicate buns from collapsing or wrinkling. Serve warm immediately!