Filling：
Salted egg yolks - 50g (from 3 eggs）
Unsalted butter - 112g (melted in room temperature)
Icing sugar - 90g
custard powder - 55g
Milk Powder - 55g
Fresh milk – 5 tbsp.
Method for filling ：
1) Mash salted egg yolks.
2) Mix icing sugar, milk powder and custard powder until combined.
3) Add in melted butter, fresh milk, mashed egg yolk and mix until incorporated. Keep in the fridge for at least 6 hours. Then roll into 20g balls and keep in the freezer. I use cling to wrap and shape it into balls.
Method for pao dough:
1) Put all the ingredients except baking powder in mixer ( I used bread maker to mix the dough for 35 min). Add in baking powder and continue to mix for another 5 minutes. (I omit baking powder). The final dough should be elastic.
2) Remove it from the mixer and divide it into smaller pieces with each 40g. Roll each piece into a smooth ball and use rolling pin to flatten it with the middle thicker than the side.
3) Assemble the pao with the egg yolk ball. I take out one piece of egg yolk ball from the freezer one at a time to assemble as the filling will get melted easily. Place the assembled pao on a piece of greaseproof paper, on the rack for steaming.
4) Let the pao proof for around 30 minutes or until it proof to double the size.
5) Steam the pao with high heat for 6 min. Turn off the heat, open the cover after 1 min.