01 - Combine golden syrup, vegetable oil, and alkaline water in a mixing bowl. Whisk until thoroughly blended and emulsified.
02 - Add flour to the wet mixture. Stir with a spatula until a cohesive dough forms. Cover tightly with plastic wrap and let rest at room temperature for 2 hours to allow proper hydration.
03 - Preheat oven to 350°F.
04 - Divide lotus seed paste into 12 equal portions (approximately 1.4 oz each). If using salted egg yolks, embed one yolk inside each paste portion and roll into smooth, seamless balls.
05 - Divide the rested dough into 12 equal portions (approximately 0.7 oz each). Keep covered to prevent drying.
06 - Flatten each dough ball into a thin disc. Place a filling ball in the center and carefully stretch the dough over it, pinching edges to seal completely. Smooth into a uniform ball.
07 - Lightly dust mooncake mold with flour. Place filled ball inside, seam side up, and press firmly to imprint the design. Release onto parchment-lined baking tray.
08 - Bake for 5 minutes to set the structure.
09 - Remove from oven. Brush surfaces lightly with egg yolk mixture, being careful not to pool the wash in the imprinted designs.
10 - Return to oven and bake for 15–20 minutes, or until golden brown. Cool completely on baking sheet.
11 - Transfer to an airtight container. Store at room temperature for 1–2 days before serving. This resting period allows the pastry to soften and develop the characteristic tender texture.