Lava Mooncake

Updated: Sep 28, 2020

This idea came to me since 2018 and it wasn't until 2019 I decided to turn that idea into a reality. An epic fail and disappointing reality it turned out to be. I literally took a chocolate lava cake, slapped it into a chocolate tart shell and called it lava mooncake. The lava oozed out even without baking.

So I thought of giving that idea another shot 2020, without all that fancy chocolate thingy. I decided to get to the primary core, which is salted egg and yes, sadly, I failed again. The lava again, oozed out, but this time, when baking process.

I was hit with frustration and disappointment again. After dealing with all that anguish, I got down to business; I took note of the steps that I did wrongly or could go wrong. I began planning out the recipe step by step and going to every single details. Finally, I got it right.

I wrote all the recipe in full details making sure you can do this too. I will also upload a detailed 7 min long recipe IGTV on my Instagram as well. The best thing is, you can prep all the ingredients a day in advance, assemble the next day and freeze after molding into mooncakes. You can take them outta freezer and bake whenever you are craving for some lava mooncakes in this Mid-Autumn festival.

Here're some tips for success:

  1. Make sure the lava is frozen solid before placing into the custard.

  2. When shaping, make sure the custard or the pastry dough has absolutely no gaps or holes.

  3. When final assembly, make sure the custard + lava isn't frozen solid. It will make be difficult to mold and will cause the pastry shell to crack.

  4. During molding, do not dust the mold with flour, instead, dust the mooncake with flour.

  5. Misting the frozen mooncakes with water spray will prevent the pastry shell from cracking.

  6. Do the egg wash immediately or as quickly as you can after 1st burst of baking process. You do not want the mooncakes to cool to room temperature, the lava will ooze out during final baking process.

  7. Brush very minimal egg wash onto the mooncake after 1st burst of baking process. Too much egg wash will also cause the pastry shell to crack.

  8. After 1st baking burst or final baking process, the mooncakes are at their most vulnerable, be extra careful and gentle.

  9. During cooling down, the top will concave and crack a little. This is normal as this is in fact, a lava mooncake. Store in airtight containers after cooled down completely.

  10. The mooncakes will look and taste better the next day.

In closing, I really hope you will give this recipe a try. Here I wish you fine lovely people a very Happy Mid-Autumn Festival!


(Make seven 2.5" / fourteen 1.5" mooncakes)

  • Salted Duck Eggs, 5

  • Lava:

  • Heavy Whipping Cream, 50g

  • Milk Powder, 10g

  • Demerara Icing Sugar, 20g

  • American Cheese / Cheddar, 1 Slice (About 20g)

  • Custard:

  • Heavy Whipping Cream, 150g

  • Unsalted Butter, 30g

  • Eggs, 3

  • Cake Flour, 50g

  • Demerara Icing Sugar, 50g

  • Milk Powder, 30g

  • American Cheese / Cheddar, 1 Slice (About 20g)

  • Pure Vanilla Paste, 1 TSP

  • Pastry:

  • Unsalted Butter Softened, 36g

  • Condensed Milk, 36g

  • Pure Honey, 36g

  • Cake Flour, 100g

  • Corn Starch, 20g

  • Egg Wash:

  • Egg Yolk, 1

  • Water, 1 TBSP


  • Oven

  • Sauce Pot

  • Cast Iron Skillet

  • Spray Bottle

  • Mooncake Mold (2.5" / 1.5")

  • Double Boiler


  1. Prepare the salted eggs.

  2. Crack salted eggs into a bowl.

  3. Spoon out the yolks and transfer into a strainer or colander.

  4. Wash under running water.

  5. Transfer into a steamer and steam for 5 mins or until the yolks are cooked.

  6. *You can use the whites for some stir-fried vegetables.*

  7. Remove from heat and set aside.

  8. Prepare the lava.

  9. Using just 3 steamed salted egg yolks, smash until it becomes a marsh.

  10. In a large heatproof mixing bowl, add cream, milk powder and demerara icing sugar.

  11. *To make demerara icing sugar, simply blitz in a spice grinder demerara sugar until powder forms*

  12. Fold until well combined.

  13. Transfer mixing over a pot of simmering water to make a double boiler.

  14. Add in cheese and the mashed salted egg yolks.

  15. Stir until smooth, well combined and the cheese has completely melted.

  16. Remove from heat and pass the mixture thru' a fine sieve.

  17. You can eat or discard the residue.

  18. You should have a smooth consistency.

  19. Transfer this lava into a freezer-friendly zip lock bag.

  20. Freeze for 2 hours.

  21. While the lava is freezing, prepare the custard.

  22. Smash the 2 remaining steamed salted egg yolks.

  23. In a sauce pot over low heat, add cream and butter.

  24. In the meantime, whisk eggs in a large mixing bowl.

  25. In another bowl, combine cake flour, icing sugar and milk powder.

  26. While still whisking the eggs, sieve in the flour mixture.

  27. Once everything has incorporated, the cream mixture should start simmering.

  28. While still whisking, gradually pour in the cream mixture.

  29. Add in cheese, mashed salted egg yolks and vanilla.

  30. Whisk until well combined.

  31. Transfer into a skillet over medium heat.

  32. Stir constantly until it becomes a dough.

  33. When you stick a spatula into the dough, it should stand upright.

  34. Remove from heat and transfer into a bowl.

  35. Cover with cling film, making sure the cling film is in contact with the custard.

  36. Chill in the fridge until ready to use.

  37. Take the lava outta the freezer. It should set a bit.

  38. Using a spatula, push the lava to the edge of the zip lock bag to form a log.

  39. Return to the freezer and freeze for 4 hours.

  40. Prepare the pastry.

  41. In a large mixing bowl, fold butter, condensed milk and honey until smooth.

  42. Fold in cake flour and corn starch in 1/2 portions.

  43. Once everything is incorporated, stop mixing.

  44. *Do not overmix.*

  45. Transfer onto a cling film.

  46. Wrap and chill in the fridge for a few hours to set.

  47. Weigh and divide.

  48. After 4 hours, the lava should be frozen.

  49. Remove from the freezer, weigh and divide into 7 if you are making large mooncakes, 14 if you are making smaller ones.

  50. Transfer onto a plate lined with parchment paper.

  51. Cover with cling film and freeze overnight.

  52. Remove custard from the fridge.

  53. Weigh and divide into 56g each if you are making large mooncakes, 28g each if you are making smaller ones.

  54. *You should have some leftover custard. You can use this leftover custard on some grilled cheese sandwich.*

  55. Roll them into balls.

  56. Transfer onto a plate lined with parchment paper.

  57. Cover with cling film and chill overnight.

  58. Remove pastry dough from the fridge.

  59. Weigh and divide into 7 if you are making large mooncakes, 14 if you are making smaller ones.

  60. Roll them into balls.

  61. Transfer onto a plate lined with parchment paper.

  62. Cover with cling film and chill overnight.

  63. On baking day, remove custard and lava from the fridge and freezer respectively.

  64. The lava should be frozen solid.

  65. *If it is not frozen solid, it will melt and ooze during the shaping process.*

  66. Shape custard balls into discs.

  67. Place the frozen lava into the discs.

  68. Wrap and roll into larger balls.

  69. *Make sure there are no gaps or holes.*

  70. Return to these balls into the freezer and freeze for 1 hour.

  71. *Do not freeze longer. It will be very difficult to shape and mold. It will also cause the pastry dough to crack.*

  72. Dust working surface generously with cake flour.

  73. Roll pastry dough balls into discs to about 1/4 inch thick.

  74. Place the custard-lava balls onto the pastry discs.

  75. Wrap and roll into balls.

  76. *Again, make sure there are no gaps or holes.*

  77. Gently roll into cylindrical, so that the mooncake mold can fit.

  78. Press the mooncake with the mold.

  79. Carefully and gently remove the mold.

  80. Transfer onto a baking tray lined with parchment paper.

  81. Freeze while working with the remaining mooncakes.

  82. *You can at this point, freeze the mooncakes for up to a month.*

  83. Freeze the mooncakes while the oven is preheating to 220 degree celsius or 430 fahrenheit.

  84. Before wacking into the oven, mist the mooncakes with a spraying of water. This is to prevent the pastry from cracking.

  85. Bake for 3 mins.

  86. While the mooncakes are baking, beat egg yolk and water until well combined.

  87. Remove from the oven, as quickly as you can, brush the mooncakes gently with the egg wash.

  88. *Make sure you are applying a thin layer of egg wash. If the egg wash is too thick, it will cause the pastry to crack. Be very gentle as mooncakes are at it's most vulnerable at this stage.*

  89. Return back to the oven and continue baking for 8 mins, rotating at halfway mark.

  90. Remove from oven and set aside to cool down completely.

  91. As the mooncakes cooled, the top will concave and crack a little. This is normal as these are in fact lava cakes.

  92. Once cooled, store in air tight containers. It can keep up to 3 days.

  93. It will taste and look better the next day.

  94. Slice and enjoy the mooncake-lavaliciousness.

Here's the detailed recipe video:

#mooncake #midautumnfestival #midautumn #saltedegg

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