- Combine sugar, yeast, oil and warm water in a bowl and gently stir to mix. Allow to rest for 10 mins. Combine flour and baking powder in a separate bowl. Pour all ingredients into a mixing bowl and knead until a smooth, non-sticky dough is formed. Kneading by mixer using a hook will take about 2 mins while hand kneading will take about 10 mins. Lightly oil a bowl and place in the dough. Cover with cling wrap and allow to rest for 1 hr in warm temperature so that the dough will double up in size.
- Meanwhile, split the red bean paste into 12 equal portions and shape them into balls.
- Once the dough has risen, punch the dough down in order to release any air bubbles. Fold and knead the dough a few times and then reshape it back into a smooth ball. Dust some flour on your working bench. Cut the dough into 2. Keep one dough covered with damp cloth and roll the other into a log. Cut the log into 6 equal sizes and shape them into smooth balls. Store the smooth dough balls on parchment paper and keep covered with damp cloth. Repeat with the other dough.
- Using a rolling pin or your palm, flatten one dough at a time. The centre of the dough should be slightly thicker while the edge should be rolled out thinner. Put one ball of red bean paste in the middle of the dough. Gather and pinch the edges to seal the bun. Repeat with remaining dough and red bean paste balls. Place all buns in a large tray and cover with damp towels. Allow to proof for 15 mins. To know if they have proofed, gently press the side of a bun. If the indentation stays, they are ready.
- Using a large, clean towel, wrap the lid of your steamer and tie with a string to secure the towel in its place. The towel helps to prevent water droplets from dripping back to the bun. If steaming with bamboo basket, the wrapping step is not required. Steam buns over boiling water for 10 mins. Remember to space the buns out a little as the buns will expand once steamed.
- At the end of the steaming time, turn of the heat and allow to rest for 5 mins in the steamer without opening the lid. Serve fresh from the steamer. To store them, simply keep them in individual zip lock bags and freeze once they have cooled down. Steam them straight from the freezer.