1large egg+ another yolk , slightly beaten (around 100g)
For the bun wrapper
2cupscake flour , or low-gluten flour
100mlmilk , or 20ml more if you are using all-purpose flour
¼cupwarm water , around 35℃
Custard filling recipe
In a small pot, combine custard powder, wheat starch and sugar together.
Heat over low heat and then add milk. Keep stirring until well mixed.
Stir in beaten egg slowly and keep stirring during the process. Add butter in. Heat until well mixed. Remove off heat and turn the filling over and over again until it can form a smooth ball and everything is well incorporated.
Set aside to cool down and then place the custard filling in fridge for at least 1 hour (depending on the temperature)or until hardened. So you can shape the fillings easily.
For the dough
Add sugar and yeast to the warm water. Wait for around 10 minutes until the yeast is well activated.
Mix other ingredients for the dough with the warm yeast water prepared in the previous step. Grasp everything together and knead until the dough becomes smooth and elastic.
Brush some oil on a large bowl and transfer the dough for the proofing. Wait for 2-3 hours until the dough is doubled in size.
Assemble the custard buns
When the dough is doubled in size, transfer to a slightly floured board and pinch the air out. Please knead forcefully for a smooth surface. And then roll into a long log; cut the log into 12 equal portions. At the same time, divide the custard filling into 12 equal portions and shape each one to a ball (make the assembling process much easier)
Take one portion out, press down slightly and then roll to a around wrappers around 8 to 10 cm in diameter. Make the edges thinner than the center.
Place on portion of the filling on the round wrapper and then seal completely. Repeat the process to finish all the buns.
Set up the steamer and let the buns reset for around 10 to 15 minutes with lid covered.
Steam on high heat for around 15 minute to 20 minutes. Turn off the fire, wait for 5 minutes before uncovering and enjoying.