Chocolate Steamed Buns

In a large bowl, combine flour, yeast, sugar, baking powder, and salt. Gradually pour in warm milk while mixing with a wooden spoon, forming a sticky dough. Add vegetable oil and knead 10 minutes until smooth and elastic. Shape into a ball, return to mixing bowl, and cover with a damp towel. Let proof in a warm spot for 1 to 1½ hours, until doubled in size.

Meanwhile, in a small saucepan over low heat, melt dark chocolate into heavy cream, stirring regularly. Remove from heat and stir in sugar, then sift in cocoa, stirring until incorporated. Cover and set aside. Once dough has risen, punch it with fist to release air bubbles. Cut eight 3x4-inch pieces of parchment paper and evenly divide dough onto them, covering with damp towel. One at a time, roll into a ball, then stretch and press into a palm-sized disk. Spoon chocolate mixture into the center, being careful not to overfill. Stretch opposite dough edges over filling until they meet, then pinch together. Take the two open ends and meet them in the middle, pinching dough to fully seal. Return to parchment seam-side down, again covering with towel. Repeat with remaining dough.

Fill a pot with water to an inch or two below the steamer. Bring to a simmer over medium heat. Arrange buns, still on parchment, inside steamer basket with space between them. (Do in batches if needed.) Cover with lid and steam for 15 minutes. Don't peek! Slide off of hot burner and let sit covered 5 more minutes. Lift lid without tilting it so the collected water doesn't fall onto the buns. Carefully remove buns and peel off parchment. Serve warm or let cool to room temperature, then store in an airtight container in the fridge (reheat in microwave with a damp towel for 30 seconds power) or freezer (steam directly from frozen for 8 to 10 minutes).