To Make Salted Egg Yolk Custard Filling
In a large mixing bowl mix salted duck eggs and sugar and beat with an electric mixer till smooth.
Add in all the other ingredients and beat till everything is well combined.
Refrigerate overnight.
Scoop up about 25-30g onto a cling wrap and shape into a round ball. Keep chilled.
To Make the Dough (Using a Breadmaker)
Add all ingredients except the dry active yeast into the bread machine bowl. Add yeast last.
Set bread machine to dough mode.
To Make the Dough (Without Breadmaker)
Mix all ingredients together to form into a smooth dough about 20 mins. Let it proof for an hour or till it rises double in size.
To Shape the Custard Baos
Once the dough is ready, remove it from the bread bowl and divide the dough into 10 portions. Roll dough into balls and cover with a damp towel as you work.
With a rolling pin, roll each dough ball into 1cm thickness but thinner on the edge before filling with a salted egg yolk custard ball. Holding the dough on your palm, start to pleat the edges of the dough together to seal the salted egg custard ball in.
Place completed bao onto baking paper squares,
Arrange completed bao into a bamboo steamer with adequate space around.
Steam bao on medium heat for 12-15 mins. Do not steam on high heat as it will cause the custard to erupt. Remove from steamer and serve immediately.