Mix 1 egg yolk with condensed milk until well combined.

Sift cake flour and baking powder into the mixture and fold with a spatula.

Cover the dough with plastic wrap and refrigerate for 30 minutes.

Divide the white bean paste into 30g portions and the dough into 20g portions. Prepare on a floured tray.

Flatten the dough like a dumpling wrapper and place the bean paste inside. Seal the edges.

Shape the pastry into a chestnut-like form. Dip the bottom in water and coat with sesame seeds.

Brush the top with beaten egg yolk for a golden finish.