These buns can be found in most Hong Kong bakeries and grandad used to always buy these from Chinatown for us when we were children.
I used my go to Hokkaido bread recipe but reduced the sugar from 60g to 40g as the filling is sweet, each bao weighs 70g uncooked dough. Please look here for the Hokkaido bread:
The filling I used:
For the whites lines I used:
30g butter
10g caster
20g plain flour