Classic moon cakes filled with smooth lotus paste are the quintessential Mid-Autumn delicacy. A traditional family dessert with rich, fragrant filling.
In a large bowl, combine all-purpose flour, golden syrup, vegetable oil, and alkaline water. Mix thoroughly until a smooth dough forms. Cover and let the dough rest for 40 minutes to relax the gluten.
Preheat your oven to 350°F (175°C). Divide the lotus seed paste into 8 equal portions. If using, cut each salted egg yolk in half and embed a yolk center into each lotus paste ball.
Divide the rested dough into 8 pieces. Roll each piece into a ball and flatten into a disk large enough to wrap the lotus paste filling.
Encase each lotus filling with a piece of dough, sealing well. Press each ball into a lightly floured moon cake mold to shape, then tap gently to release.
Arrange formed moon cakes onto a parchment-lined baking sheet. Lightly brush with beaten egg for a glossy finish. Bake for 12 minutes, remove, cool for 10 minutes, then brush with egg again before returning to bake another 8–10 minutes until golden brown. Cool thoroughly before serving for best flavor and texture.