Thousand Layers Lava Custard Mooncakes
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Try something new for the Mid-Autumn Festival with these Thousand Layers Lava Custard Mooncakes, featuring flaky layers of pastry crust stuffed with sweet custard and oozing salted egg lava fillings.
Mooncake festival is just around the corner and it is that time of the year that families start to buy or make their favorite mooncakes. Today, I want to share this Thousand Layers Lava Custard Mooncakes recipe to celebrate the festival.
About Mid-Autumn Festival
The Mid-Autumn Festival, also known as the Moon Festival or Mooncake Festival, is a traditional festival celebrated in Chinese culture. The festival is held on the 15th day of the 8th month of the Chinese lunisolar calendar. On this day, the Chinese believe that the moon is at its brightest and fullest size, coinciding with harvest time in the middle of Autumn.
Making and sharing mooncakes is one of the traditions during the festival. In Chinese culture, a round shape symbolizes completeness and reunion. Thus, the sharing and eating of round mooncakes among family members during the week of the festival signifies the completeness and unity of families.
What Are Thousand Layers Lava Custard Mooncakes?
These Thousand Layers Lava Custard Mooncakes combine the outer pastry of Dan Huang Su (the pastry mooncakes with salty egg yolk) and the fillings of Lava Custard Mooncakes. The pastry is similar to puff pastry and is made by laminating a water-based dough with an oil-based dough, and then stuffing it with sweet custard and runny salted egg lava fillings.
When you cut or bite the mooncakes in the middle, the lava filling will ooze out and that is the main highlight of these mooncakes. The texture of these mooncakes is fun with its flaky dough, sticky custard, plus that runny lava filling. It is very buttery, lightly sweet yet salty.
Special Ingredients to Make Lava Custard Mooncakes
- Salted egg yolks. They are the yolks of salted duck eggs. Salted duck eggs are the result of an age-old method of preserving fresh eggs. Traditionally, they are made by covering eggs with clay made from plant ash, dirt, salt, and water. The eggs are then left to sit for 30 to 40 days. While they sit, water exits the egg and is replaced by salt, in a process known as osmosis. The egg whites turn thick and slimy while the round yolks solidify and turn bright and orange-red in color during the salt curing process.
- Custard powder. Custard powder is not dried, powdered custard. It is actually a powdered mix used to make custard, and it is very similar to the type of mix used to make instant puddings. Typically, you can add only water or milk to turn the powder into a custard. Why use custard powder in this mooncake recipe? The custard made with custard powder is more stable and uses less egg which lowers the possibility of curdling. The powder also contains flavorings that make the custard richer and taste better than custard made with just eggs.
- Milk powder. To enhance the flavor.
- Evaporated milk. Evaporated milk starts out as fresh milk and is heated to drive off more than half of the water. The resulting liquid is creamier and thicker than regular whole milk. Adding this to baked goods instead of regular milk makes the result taste richer.
- Condensed milk. To sweeten and add flavor to the custard.
- Shortening. The pastry involves making two types of dough, an oil dough and a water dough. Have you heard the old saying “oil and water don’t mix”? That is the principle behind why this dough works. Traditionally, Chinese people make this pastry using pork lard. As that is more difficult to obtain, shortening is the easiest substitute to work with. You can also use butter, but it is more complicated because butter contains 16-18% water and you need to melt the butter and cook it until it turns clear and not opaque to remove the water content.
Make These Mooncakes in Advance
None of the components of mooncakes are particularly difficult, but they all take a bit of time. I recommend taking 2 days to make these mooncakes.
- Day 1. Make the lava and custard filling. The lava filling takes hours to freeze so I recommend taking a full day to make it.
- Day 2. Make the skin dough, assemble, and bake the mooncakes.
How to Shape the Pastry
The pastry dough may sound a bit daunting to make, but I promise this one is very easy to work with.
- Wrap the oil dough in the water dough and form a ball.
- Roll the dough ball into a long, flat strip. Roll it tightly like a Swiss roll.
- Place the roll vertically and roll it again into a long, flat strip.
- Roll it tightly like a Swiss roll.
- Use your finger to press the middle of the rolled dough.
- Fold the swirled ends to the center and press them down.
- Flatten thinly with a rolling pin.
Pro Tips
- Work the fillings in small batches. The lava will easily melt after being taken out from the freezer. I recommend you take out about 3 lava fillings at one time from the freezer to prevent the other 9 from melting.
- Work fast. Or the lava filling will melt.
- Keep the fillings cold-frozen. So handling and shaping will be easier
- Rest the dough. This helps to relax the gluten, making it more elastic. The longer the dough is rested, the easier it is to work with.
- Dust the mooncakes with flour before shaping. This prevents them from sticking to the mold.
- Watch the tutorial video. Make sure you watch the video for a visual guide on how to make these Lava Custard Mooncakes.
How to Store
Let the mooncakes cool down completely and store them in an airtight container. They will last for 3 days at room temperature or up to a week in the refrigerator. Reheating is recommended for the best molten lava experience.
More Mooncake Recipes
Ingredients
Lava Filling
- 3 salted egg yolks, 45 gr
- 50 gr heavy whipping cream
- 20 gr salted butter, room temperature
- 20 gr granulated sugar
- 10 gr evaporated milk
- 10 gr milk powder
Custard Filling
- 2 salted egg yolks, 30 gr
- 1 egg
- 75 gr evaporated milk
- 40 gr milk
- 40 gr granulated sugar
- 30 gr milk powder
- 25 gr custard powder
- 25 gr salted butter, room temperature
- 12 gr condensed milk
- 12 gr cake flour
Thousand Layers Pastry (Water Dough)
- 100 gr all-purpose flour
- 15 gr confectioners’ sugar
- 1/8 tsp salt
- 35 gr unsalted butter, room temperature
- 45-50 gr ice water
Thousand Layers Pastry (oil dough)
- 100 gr cake flour
- 55 gr shortening
Toppings
- 1 egg yolk
- Black sesame seeds
Instructions
It is recommended to take 2 days to make this Thousand Layers Lava Custard Mooncakes recipe:
- Day 1. Make the lava and custard filling.
- Day 2. Make the skin, assemble, and bake the mooncakes.
Prepare Salted Egg Yolks
- Crack open 5 salted duck eggs and separate the yolks from the whites. Clean the yolks on running water. Place the yolks on a heat-proof plate or bowl.
- Spray the yolks with a small amount of Shaoxing wine/baijiu/other alcohol to remove the fishiness.
- Place the yolks on the preheated steamer and steam on medium heat for 8-9 minutes or until cooked.
Lava Filling
- Blend 3 steamed salted egg yolks and other ingredients with an immersion blender or blender until smooth.
- Transfer the mixture to a non-stick frying pan. Heat on low heat and cook until the mixture is just warm to dissolve the sugar. Do not boil.
- Line a small freezer-friendly container with cling wrap. Transfer the mixture to the container. Freeze for 2-3 hours or until firm to touch.
- Remove the frozen lava filling from the container. Use a knife to divide it into 12 pieces equally (12 gr each). Shape into balls and place them in a freezer-friendly airtight container. Make sure to work fast or the lava filling will melt.
- Freeze the balls for at least 4 hours or overnight.
Custard Filling
- Blend 2 steamed salted egg yolks and other ingredients with an immersion blender or blender until smooth.
- Transfer the mixture to a non-stick frying pan. Heat on low heat. Keep stirring the mixture with a spatula while cooking and cook until it thickens and turns into a dough. Don't overcook or it will turn dry and crumbly.
- While the dough is still hot, cover with a cling wrap to prevent it from drying out. Once the dough has cooled completely at room temperature, store it in the refrigerator until using it.
Thousand Layers Pastry
- Make water dough. Sift all-purpose flour, confectioners' sugar, and salt into a medium ball. Add butter and ice water. Mix with a spatula until a dough forms. Knead with your hands or mixer with a dough hook attachment until the dough turns smooth and elastic. To test the dough, stretch it into a thin semi-transparent sheet and it should hold well. Cover with a cling wrap. Rest the dough for at least 15 minutes.
- Make oil dough. Sift cake flour into a medium bowl and add shortening. Mix and press it together with your hand until smooth. Cover with a cling wrap. Set aside.
Prepare The Filling
- Remove the custard filling from the refrigerator. Divide the custard filling into 12 pieces equally (27 gr each). Shape into balls.
- Take a custard ball and make a deep well in the middle with your thumb. Insert one frozen lava ball into the middle and then close the top and reshape it into a ball. Repeat for the remaining pieces. Make sure to work fast or the lava filling will melt. Just take out 3 lava fillings from the freezer at one time to prevent the lava fillings from melting.
- Freeze the filled custard back into the freezer until you are ready to assemble the rest of the mooncakes.
Prepare The Pastry Dough
- Divide the water dough into 12 pieces equally (15 gr each). Roll them into smooth balls. Cover the balls with a cling wrap to prevent them from drying out. Set aside.
- Divide the oil dough into 12 pieces equally (13 gr each). Shape into balls. Cover the balls with a cling wrap.
- Place a ball of oil dough on the working surface with the seam side up. Flatten the dough with a rolling pin, about 2.5 inches/6.5 cm in diameter. Place a ball of oil dough in the center and lift the edges of the water dough to cover the oil dough. Pinch the edges of the water dough to seal. Repeat with all pieces of dough.
Assemble The Mooncakes
- Preheat the oven to 425F/220°C. Line a baking sheet with parchment paper or baking mat.
- Take a formed ball and place it on the working surface with the seam side up. Gently roll it into a long strip, about 5.5 inches/14 cm. Roll it tightly like a Swiss roll. Turn the dough vertically and roll it again into a long strip, about 5.5 inches/14 cm. Roll it tightly again. Cover and set aside. Repeat with the remaining balls.
- Beginning with the first roll you made, take a roll and press in the middle so the swirled ends are pressed out. Then, fold the swirled ends into the center and press them down. Roll thinly with a rolling pin into 5 inches/12.5 cm in diameter.
- Place the filling in the center. Lift and stretch the dough over the filling ball to cover completely. Pinch to seal. Place on the prepared baking sheet with the seam side down. Repeat with all the dough and filling.
- In a small bowl, lightly beat the yolk. Brush a thin layer of the egg wash onto the tops of the pastry. Wait for 5 minutes and brush a second layer of yolk.
- Wet your fingertip with water and dip it into the black sesame seeds so the seeds stick to your finger. Tap the top of each pastry to decorate.
- Bake for 12-15 minutes or until the top is golden brown. Transfer the mooncakes to a cooling rack to cool completely.