140mLgolden syrup, (okay to sub honey; mooncakes will be less golden)
1tspalkaline water, kansui
1/3cuppeanut oil
1 2/3cupall-purpose flour
Egg Wash
1egg yolk
1tablespoonwater
12cooked salted duck egg yolks
Instructions
Taro and Yam Filling
Wash and peel taro root with potato peeler. Wearing gloves for this step is helpful because raw taro can leave skin feely waxy and itchy. Cube taro into 1 inch cubes. Repeat steps for purple yam.
Place taro and purple yam cubes into a steamer or steaming basket. Steam until tender to the fork, roughly 30 - 40 minutes.
Remove taro and yam from steamer. Using a fork or potato ricer, mash the root vegetables into a smooth paste.
Add salt, sugar, vegetable oil into mixture. Mix until well combined and paste is smooth.
Set aside and let the filling cool.
Mooncake Skin
Whisk together the golden syrup, oil, and alkaline water.
Then add the mixture to the flour, and use a rubber spatula to fold and combine everything into a soft dough. Do not overwork the dough.
Cover the dough and let it rest in the refrigerator for an hour.
Assembly
Weigh out twelve 60-gram scoops of taro filling and gently shape each portion into balls. Set aside.
Divide and weigh the dough into twelve 25-gram pieces. Keep any leftover dough to use for mending when dough cracks during shaping process.
Take on of the taro balls and make a deep well in the middle. Insert one salted duck egg yolk into the well. Close the top and reshape into a ball, trying to make sure the egg yolk is as centred as possible. Repeat for the remaining 11 portions of filling.
Lightly dust dough balls with flour. Roll out dough ball on a piece of parchment paper into 4-inch round.
Put one piece of the filling in the centre of the rolled out dough. Carefully use the parchment paper to fold the dough onto the filling so that it wraps around the filling. It is okay if your dough cracks - we can reshape it and patch any holes with the reserved dough.
Turn the opening side up and slowly press together to close the opening, to cover all surfaces of the filling. Keep the distribution of dough as even as possible.
Brush on a bit of flour into mooncake mold. Place assembled dough ball into the mould. With the mold facing upwards, apply gentle pressure to shape the dough ball into the mold cavity. Flip the mold over and press the mooncake down with the top pressure bar. Gently guide the mooncake out of the mold.
Place moon cakes onto a parchment-lined baking sheet.
Preheat oven to 325 degrees.
Using a spray bottle, gently mist the moon cakes with water. Alternatively you can very gently use a pastry brush to brush on a very thin layer of water onto the top of the moon cakes. This will prevent the moon cakes from cracking when baking.
Immediately put the mooncakes in the oven and bake for 5 minutes.
While the mooncakes are baking, prepare the egg wash.
Once five minutes are up, take mooncakes out of the oven. Brush a thin layer of egg wash onto the mooncakes, making sure there are no large puddles of egg wash. Large wells of egg wash will make your moon cake design less defined.
Bake for an additional 15 minutes until golden brown.
Remove mooncakes from oven. The mooncakes will look dry at this point (vs. the glossy sheen of moon cakes from the store). Store the cooled mooncakes in an airtight container for a day and the skin will develop the glossy finish we associate with traditional mooncakes. You will start to see this sheen develop within the first couple of hours.