Mix egg, sugar, salt, condensed milk, and melted butter in a bowl until combined.

Sift cake flour and almond flour together into the mixture and stir until a dough forms.

Cover the dough with plastic wrap and refrigerate for 1-2 hours.

Mix chopped walnuts and pecans into the white bean paste for the filling.

Divide the filling into 30g portions and roll into balls.

Divide the dough into 25g portions and roll into balls.

Flatten each dough ball and wrap it around the filling ball, sealing completely.

Dust the wrapped dough lightly with flour and press into a mooncake mold to shape.

Bake at 190°C for 5 minutes, then remove and brush with egg wash.

Return to the oven and bake at 180°C for 15 minutes. Adjust time as needed based on your oven.

Cool completely on a wire rack before storing.