1. Mix the golden syrup, OKI sunflower oil, and alkaline water until well combined. Add the flour to the mixture and knead until a dough is formed. Cover it with cling wrap and allow it to rest for at least one hour.

2. Bake the salted egg yolks in a preheated oven at 180°C for 5 minutes.

3. Divide the filling into 60g portions, shaping each into a round wrapper. Place a salted egg yolk in the center, then gently push the paste upwards to completely seal the yolk.

4. Divide the dough into 25g portions, flattening each into a round wrapper. Use the same method to wrap and seal the filling, then roll it into a ball.

5. Coat the mooncakes with a thin layer of flour and shake off any excess. Place them on a baking tray.

6. Place the mooncake mold on the dough and gently press the piston downward. Repeat this process several times to achieve a perfect shape; otherwise, the mooncake may appear lopsided or have a blurred pattern.

7. Bake the mooncakes in a preheated oven at 170°C for 15 minutes. Once done, remove them from the oven and allow them to cool for 5 minutes. Lightly brush the tops of the mooncakes with egg wash. Continue to bake at 170°C for another 10-15 minutes or until they turn golden brown.

8. Allow the mooncakes to cool on a rack, then store them in an airtight container for 1 day.