Lightly toast melon seeds in oven at 160°C for about 8 minutes. (optional step)
Spray water all over the mooncakes to prevent the dough from cracking. (Edit: I have tested and found that it is better to leave out this step. You can prevent dough from cracking by lengthening cooling time to 10 to 15 minutes).
Remove from oven and cool for 5 minutes. (Edit: better to cool for about 10 to 15 minutes). Brush the mooncakes with egg wash.