If you just want to enjoy a piece of sweet flaky mooncake, Vietnamese sandwich stores and bakeries are the place to go. If you have plenty of time at hand and little trust for unknown kitchens, then hit the market to find these ingredients for a batch of 12 bánh bía:
1. The skin dough
- 375g all purpose flour (Pillsbury preferred)
- 110g confectioner sugar
- 80g corn/canola oil
- 100ml coconut milk (Chef’ Choice preferred)
- 50ml water.
Add flour, sugar, oil and coconut into a mixing bowl, then slowly add water while kneading until the dough is smooth. Don’t need over 2 minutes or the dough would be too hard to flatten later. Cover with cling wrap and let the dough sit for 1 hour. Divide into 12 balls afterwards.
2. The inner layer dough
- 125g tapioca flour
- 95g wheat flour
- 110g corn/canola oil
Mix the flours and oil together. Do not knead. Let sit for 1 hour, then divide into 12 balls.
3. Bean paste filling with durian flavor and salted egg yolk
- 400g mung bean (peeled and split)
- 300g sugar
- 1 cup oil
- 1 tbs maltose sugar
- 1 tsp baking soda
- 1/4 cup wheat starch (the type used for potsticker)
- 200g durian flesh (ground up in a food processor)
- 12 salted eggs
- 1 slice of ginger
- rice wine
Separate the egg yolks from the whites, wash with cold water, then soak the yolks in rice wine and finely chopped ginger for about 30 minutes. Take the yolks out the wine mixture and quickly soak them in vegetable oil. Finally, bake the yolks on aluminum foil in 300F for 10 minutes.
Soak the mung beans in water and baking soda until they soften. Rinse them with cold water, steam, wait until the beans cool to make a fine paste with the food processor.
In a non-stick pan, simmer the bean paste with 200g sugar, 2 tbs maltose, and 1/4 cup oil over low heat. In another pan, mix 1/2 cup oil with 100g sugar to make caramel on low heat. It should be golden brown, or the pastry filling would be bitter.
When the sugar has caramelized, pour the bean paste into it and mix until there is no visible sugar. Add 1/4 cup of oil and wheat starch and continue simmering. Lastly, add durian paste and stir until the bean mixture no longer sticks to the utensil. Let the paste cool and divide it up to 12 portions.
4. The egg wash
- 1 egg, room temperature
- a pinch of salt (kosher salt preferred)
- 1 tbsp water
- 1 tsp sesame oil
- 1 tsp cashew oil
- 1 tsp dark corn syrup
Mix all ingredients into a blend.
5. Make the cake
- Flatten each ball of skin dough, then use it to wrap the ball of inner layer dough (like a dumpling). Keep the dumplings moist until all 24 balls of skin dough and inner layer dough are paired up.
- Gently flatten each dumpling into oval shape about 2mm thick, roll the sheets into Swiss-rolls.
- Repeat the flattening process with the Swiss rolls, then let the dough balls rest for 15 minutes. Make sure that during this process the skin dough always covers the inner layer dough, or the pastry will have a rough surface after baking. If the dough is too tough, let it sit for 5-10 minutes. Do not exert too much force while flattening.
- Flatten the dough balls again into disks, and use them to wrap up the balls of bean paste (each with an egg yolk inside).
- Preheat oven to 400F
- Bake the pastries for 15 minutes, then take them out to brush egg wash on one side, and continue baking for another 10 minutes.
- Let the pastries cool and oil release for a few days.
6. Eat the cake
(Caution: it may be too fatty and sweet to eat whole, one quarter at a time is the usual safe quota)
Recipe translated from source.