Salted egg yolk lava mooncakes are perhaps one of the best modern renditions of traditional mooncakes. Cutting into the buttery, crumbly pastry reveals a molten salted egg yolk lava centre that’s enrobed in an aromatic egg custard. With a perfect balance of sweet and savoury, it’s not an exaggeration to call these mooncakes heavenly. [Go straight to recipe]
Decadent Salted Egg Yolk Custard Mooncakes
Unlike the Snow Skin Mooncake Baking Kits we launched this year, these Salted Egg Yolk Lava Mooncakes are baked.
They look similar to traditional Cantonese mooncakes, but they have a buttery and crumbly skin made of pastry that’s similar to a tart crust.
Read more: A Basic Introduction To Tart Making If You're Interested But Afraid To Start (Tart Tips, How To Blind Bake And Tools You'll Need)
Instead of putting a whole egg yolk in the middle, we’re giving these mooncakes a modern twist.
These ultra-decadent mooncakes have a molten salted egg yolk lava core that oozes out once you cut into it! It’s similar to the centre of this Lava Cake, but with a rich and buttery salted egg yolk flavour.
Tackling this recipe requires quite a bit of time and preparation, but the satisfaction of slicing open a molten lava core is worth it.
Making the salted egg yolk filling, custard, and pastry skin are all done in different steps, and each one takes at least an hour to complete.
For the best results, read the recipe thoroughly before starting and get everything prepared!
Tips for a Smooth Filling and Custard
When you’re making the salted egg yolk molten lava filling, it’s important to whisk all the ingredients until they’re completely smooth. Using a quality hand whisk will ensure that all ingredients are well incorporated and lump-free.
The same goes for making the custard that’ll be used to wrap around the salted egg yolk core. You want a completely smooth mixture, just like the filling for our cream puffs.
When you’re heating the custard, always use low heat and scrape the bottom of the pan continuously. If your temperature is too high, the custard might start to curdle and form lumps, so be patient!
Stirring and scraping distributes heat evenly, so it prevents your custard from curdling and scorching. Once it reaches the desired thickness, transfer it immediately to a heatproof bowl to stop it from cooking.
These two mixtures have to be cooled completely before covering with cling wrap.
If they’re covered when still hot, water droplets will form and negatively affect their texture (remember how to treat a cheesecake before refrigerating? That’s how you do it!).
Take the time to freeze them until firm, so handling and shaping will be easier.
Making a Buttery, Crumbly Mooncake Pastry
The pastry layer for these mooncakes is similar to a tart crust.
It’s buttery and crumbly, with a pleasant melt-in-your-mouth texture. And to get the desired results, always use the correct techniques, just like how you’d make any baked goods.
When the dry and wet ingredients are still in separate mixing bowls, mix each one of them thoroughly. This is the only chance to ensure everything is distributed evenly, without having to worry about toughening the dough.
After pouring the dry ingredients into the wet mixture, fold them in until just incorporated.
We want a delicate texture, and overmixing will create too much gluten—the same thing that makes cookies tough and dense.
Read More: Why Did My Cookies Fail? Here Are 10 Possible Reasons & Solutions Why Your Homemade Cookies Failed
To ensure that all your mooncakes will bake in the same amount of time so that you don’t end up with over or under-baked mooncakes, portion the pastry dough equally. A digital scale would be highly recommended in this case!
Assembling the Mooncakes
Molding picture-perfect mooncakes might be tricky at the start, but all it takes is some practice! Here are some of our tips:
1. Cover the filling completely.
These mooncakes require you to wrap the salted egg yolk filling with custard, before further wrapping it with the pastry dough.
When you’re wrapping the custard with the pastry dough, cover it entirely and make sure there are no cracks.
If there are any cracks (no matter how small), the custard and filling might seep out when baked. It will not affect your mooncakes’ flavour, but they won’t look as beautiful!
2. Make the patterns stand out.
To ensure that the beautiful patterns on your mooncakes stay after they’re baked, press your mooncakes into the mold firmly and deep enough.
The pastry will puff up slightly during baking. Without giving the mooncakes deep creases, the patterns might not be very prominent after baking.
3. Know how long to bake the mooncakes.
Baking is an essential part of making any type of baked good.
These mooncakes require two steps of baking. You’ll first have to bake the mooncakes for about 4 minutes before adding a layer of egg wash, then baking for another 6–10 minutes.
Overbaking these mooncakes will result in a non-flowy core, so we recommend doing a test bake on 2 or 3 mooncakes first, before proceeding with the next ones. This will help you figure out the exact timing to get your mooncakes to have a flowy interior.
Different ovens are built differently, which means baking your mooncakes might take a little more or less time. It doesn’t take long to bake these mooncakes, so watch them closely!
If you want to ensure that your oven is properly calibrated, an oven thermometer will be very helpful in telling you the true temperature of the interior of your oven.
The egg wash layer adds a beautiful golden brown colour to your mooncakes, but do not overdo it as it will mask the prints on your mooncake.
Using a pastry brush will help you apply a thin and even layer of egg wash onto your mooncakes!
Watch video tutorial:
Molten Salted Egg Yolk Lava Baked Mooncake
yields 15 x 2" mooncakes
Salted Egg Yolk Filling
60g salted egg yolk powder (1)
30g unsalted butter (1)
45g condensed milk (1)
4g custard powder
60g cake flour (1)
150g heavy cream
30g unsalted butter (2)
30g milk powder
25g salted egg yolk powder (2)
70g granulated sugar
3g vanilla extract/essence
72g condensed milk (2)
72g unsalted butter, softened (3)
230g cake flour (2)
40g corn flour
1 egg, for egg wash
1x mooncake mold
For Salted Egg Yolk Filling
- In a medium bowl, whisk together salted egg yolk powder (1), butter (1), condensed milk (1), milk, and custard powder until it becomes a smooth paste-like texture.
- Cling wrap and refrigerate the mixture for about 45-60 mins or until it has completely set and firmed up slightly. Meanwhile, continue with the custard.
- In a mixing bowl, whisk together 3 eggs and cake flour (1) until pale and fluffy with no visible lumps.
- In a saucepot, heat and stir the heavy cream and butter (2) over medium heat. Once the butter has melted and the cream starts to simmer (not boil), carefully pour the cream mixture into the egg mixture (from previous step) while whisking.
- Add milk powder, salted egg yolk powder (2), granulated sugar, and vanilla, whisking after each addition. Pour the mixture back into the pot and cook it over low heat.
- Use a spatula to scrape the bottom and sides of the pot continuously while cooking, but do not stir too vigorously.
- Scrape and fold the custard mixture when it begins to hold its shape loosely. The custard should slide off your spatula, leaving little to no residue. This will take about 15-20 mins of constant stirring and cooking of the mixture.
- If the mixture starts to scramble, remove the pot from the heat, lower the heat, and continue cooking and stirring. Use the back of your spatula to break the lumps.
- Once done, remove the mixture from heat and transfer it back into a bowl. Let it cool slightly, about 5 mins, before covering it with cling wrap and refrigerating until it is firm, about 45-60 mins. Meanwhile, proceed with the pastry.
- In a large mixing bowl, whisk together honey, condensed milk (2) and softened butter (3) until well combined.
- Use a spatula to fold in the cake flour (2) and corn flour until a dough forms.
- Using your hands, gather the dough and form a square block. It should be soft but not sticky. Cling wrap the dough and refrigerate it while you start with the assembly.
- Portioning filling: Divide filling into 15 equal portions. Using a teaspoon, scoop each portion equally (about 11g each) and place onto a plate/tray by using your finger to slide the filling off the spoon. Freeze them for about 45-60 mins. Meanwhile, start portioning the custard.
- Portioning custard: Divide custard into 15 equal portions, about 24-27g. Exact weight may vary depending on the shrinkage of your custard during the cooking process. Work fast before the custard gets too sticky to handle.
- Chill custard portions in the fridge for about 30-45 mins, or until you're ready to wrap the portioned filling.
- Wrapping filling with custard: Flatten a custard portion with your palms/fingers (flatten it more for easier wrapping) and wrap it around a portioned filling. Roll to smoothen the ball. Repeat for the rest.
- Freeze them for about 2-4 hours (or preferably overnight) or until they are fully firm. This will make it easier to wrap them with the pastry. If custard/filling portions are too sticky during assembly, refrigerate for about 10-15 mins. Meanwhile, proceed to the next step.
- Portioning pastry: Weigh out 30g of pastry dough. Roll into a ball and place on a plate/tray. Repeat for the rest. Chill pastry balls until the frozen custard balls are ready to be wrapped. Let dough sit at room temperature for about 10-15 mins if it is too firm to work with.
- Wrapping custard balls with pastry: Flatten portioned pastry dough using your palms/fingers. Place custard ball in the middle and wrap pastry around. Use your fingers to spread pastry evenly and fill any empty gaps. Roll the ball to smoothen and even out the pastry. Repeat for the rest.
- Choose your preferred design template and fix it into your mooncake mold.
- Gently roll an unbaked mooncake ball into an oval shape, ensuring that the custard ball is centralised. Place it in the mooncake mold and press the base gently with your fingers. Plunge it down onto the tray/plate. If your mooncake gets stuck, gently release the mooncake edges before carefully pulling it away from the mold. Repeat for the rest of the balls.
- Freeze molded mooncakes for another 15 mins before baking, or until ready to bake.
- Preheat your oven to 230°C.
- Egg wash: Meanwhile, beat one egg in a small bowl using a fork. Pass the egg through a sieve into another bowl. Use your fork to stir the egg so that it can pass through the sieve.
- Line a baking tray with parchment paper and bake the mooncakes for 4 mins. Start with 2 to 3 mooncakes first to familiarise yourself with your oven's hot spots. Coat the mooncakes with egg wash using a pastry brush, and bake for another 6-10 mins until the mooncake is completely set and golden brown on top.
- Serve warm for best results.
Storage Instructions: You can save some unbaked mooncakes to bake later. Store them in a container in the freezer for up to a month. Note that the baking time might be slightly longer if the mooncakes are baked straight from the freezer. Spray some water onto the mooncakes before baking, as they might be dry from storing in the freezer.
Tip for gifting/storing baked mooncakes: If the mooncakes are going to be reheated, slightly under-bake the mooncakes, then reheat again at 200°C for about 2-3 mins before serving until they’re golden brown and all warmed up.
Decadent Salted Egg Yolk Custard Mooncakes
These salted egg yolk lava mooncakes are decadent, best-served warm, and will definitely impress your family and friends! While they might take a bit of work, nothing beats the satisfaction of slicing into these warm, crumbly pastries and watching the molten lava flow out.
For more mooncake and mid-autumn related reads, check out the following articles:
Love this recipe? Get priority access to more free recipes, baking tips and guides sent straight to your inbox here.
Trying this recipe out? Make sure you hashtag #bakestarters on Instagram so we can see your wonderful creations!