For the Filling:

1. Steam salted eggs for about 5-10 minutes.
2. Mix melon seeds with lotus paste.
3. Divide lotus paste and roll into balls.
4. Make a hole in the center and insert the salted egg yolk, then fold & roll into ball shape.

For the Mooncake:

1. Mix golden syrup, oil and alkaline water in a bowl.
2. Add flour to mixture and knead into a soft dough. Leave dough to rest for 30 minutes.
3. Divide dough into small portions.
4. Flatten dough. Wrap the dough neatly over the lotus paste ball.
5. Press dough into a mooncake mould dusted with flour. Knock mould on all sides and slide the mooncake out.
6. Place mooncake on greased tray. Water spray lightly on the mooncakes. This will prevent the mooncakes from cracking. Bake in preheated oven at 180C for 7 minutes. Take it out & brush with egg, then bake for another 13-15minutes. Remove from oven and let mooncakes cool.
7. Mooncakes can be eaten on the 3rd day after baking.

You can customize your dough/filling proportions according to the size of your mooncake mould (small/medium /large). Dough is about 40% vs 60% filling to make up the whole mooncake.