Nai Huang Bao (Steamed Custard Buns)

To prepare the custard filling, combine Egg yolks, 80 grams of Caster sugar, Custard powder, Milk powder, Coconut milk, and Evaporated milk in a heatproof bowl. Whisk until smooth.

Place the bowl over a pot of simmering water (double boiler method), ensuring the bottom of the bowl does not touch the water. Continuously stir the custard mixture with a whisk or spatula until it thickens to a paste-like consistency, about 10-15 minutes.

Remove the bowl from heat and stir in the Unsalted butter until fully melted and incorporated. The custard should be smooth and glossy. Cover the custard with plastic wrap, pressing it directly onto the surface to prevent a skin from forming, then chill in the refrigerator for at least 2 hours, or until firm enough to handle.