Baked Custard Milk Buns (Nai Wong Bao) – Tang Zhong Method

Super soft fluffy milk buns made with water roux method (tangzhong) are filled with delicious milk custard (nai wong) and baked to perfection.

My dad was a huge fan of bread, cakes, pastries, and pretty much all the other sweet treats too. I remember having wide varieties of mini cakes, buns, bread, Indonesian kue kue for afternoon snacks every day. He would go to his favorite bakery shop and brought home loads of these good stuffs. My mom is a great cook, but she is never a baker nor does she has any interest in sweets at all. She’s probably one of the very few people I know that doesn’t care much for any cakes and sweets. Yeah…they are the polar opposites. I’m truly not a baker. Honestly, I love to cook more than baking. Baking required precision, which I just don’t have!! I’m a pinch of this and that person. Lately, though I’ve enjoyed baking more and more. I’m still a horrible baker, but some successes such as croissants, brioche, and French macarons have given me some confidence to explore more in the baking department.

These buns are made using Tang Zhong method (water roux starter). From what I read, this method comes from Japan and it helps to keep your baked bread and buns soft and fluffy, even after days. It’s truly a game-changer for me. It’s basically a mixture of water and flour cooked into a paste and then mix into the dough. A little bit extra work, but SOOOOO worth it!!! You can read more about it from this Soft and fluffy Hokkaido Milk Bread.

I baked the buns in this gorgeous 12-inch cast-iron skillet by Victoria Cookware. Seriously, the best decision I’ve ever made. The even heat distribution from cast-iron gives these buns their nice color and the bottom is not over browned and overbaked, which is almost always the case when I use my regular baking pan. The skillet feels very substantial and you know it is of high-quality and made in Columbia.

It’s incredible how soft and fluffy these buns are. The kids love these buns so much. It’s time to make more!! Thank you so much Victoria Cookware for the 12″ cast-iron skillet. It will be put into many good uses in this house for many years to come!

Baked Custard Milk Buns (Nai Wong Bao) - Tang Zhong Method

5 from 2 votes

8 large buns

Prep: 35 minutes

Cook: 30 minutes

Proof the dough 1 hour 40 minutes

Total: 1 hour 5 minutes

Pumpkin custard milk buns are so soft and fluffy, they just blow my mind! The buns are made using water roux (Tang Zhong) method and filled with delicious creamy custard.

For baking/ kueh making: I highly encourage to weigh ingredients with a digital kitchen scale instead of using measuring cups as they are not very accurate especially when it comes to recipe that requires precision.

GRAMS TO CUPS CONVERSION (UNSIFTED)

INGREDIENTS

ROUX STARTER (TANG ZHONG):

• 15 gr bread flour
• 90 ml whole milk

DRY INGREDIENTS:

• 300 gr bread flour
• 5 gr instant yeast
• 5 gr milk powder

WET INGREDIENTS:

• 120 ml whole milk
• 1 egg about 50 gr - lightly beaten

INGREDIENT TO ADD LAST TO THE DOUGH:

• 40 gr butter softened
• 1/2 tsp salt
• 2 Tbsp sugar see notes

EGG WASH:

• 1 egg beaten
• 1 tsp water

TOPPING:

• Sesame seeds for sprinkling - optional

CUSTARD FILLING:

• 2 large eggs
• 100 gr milk
• 60 gr sugar
• 1/8 tsp salt
• 30 gr all-purpose flour
• 30 Tbsp milk powder
• 40 gr unsalted butter

INSTRUCTIONS

PREPARE CUSTARD FILLING (can be done the day before):

• Whisk egg, sugar, and salt in a bowl. Gradually add in milk as you are whisking. Sift in the flour and milk powder into the mixture and whisk again. There will be some lumps. Don't worry
• Put the saucepan over low heat. Add butter and continue to stir until butter started to melt and continue to cook until the custard thickened. Remove to let the custard cool down and it will thicken further. Let it cools down completely. Cover and refrigerate if not using on the same day
• When the custard is firm, you can roll them into 8 large balls for easier wrapping later

PREPARE TANG ZHONG:

• Place milk and the bread flour in a small saucepan. Whisk until there is no more lumps. Cook this mixture over medium heat until it is thickened, about 5 minutes or less. Remove from the heat and let it cool down completely

MAKE THE DOUGH:

• Mix all the dry ingredients together in a mixing bowl. Make a well in the center and pour in the wet ingredients and the tang zhong you made earlier. Use a dough hook attachment to knead the dough until all the crumbly dough starts to come together into one mass, it may take about 2-3 minutes for this to happen. Don't be tempeted to add any liquid. You may need to stop halfway and scrap the dough off the hook and the sides of the bowl and knead again several times
• Once it comes into a dough, stop the machine. The dough will not be smooth, don't worry.Cover the dough and let it rest for 20 minutes. This is an important rest that bakers refer to as an autolyse (though in our case it's a short one. Read my post above for detail)
• After the rest, turn on and knead the dough again and knead for 1-2 minutes until it is a bit smoother. Then add the salt and sugar into the dough. Continue to knead until the dough is relatively smooth. You need to stop and scrape the dough off the hook and the bowl several times during this process. I promise it's worth the effort!
• Once you have a smooth dough, turn the machine back on again to knead and gradually add in the softened butter a bit by a bit. The dough will turn into a REAL sticky mess again because of the butter, just keep kneading and stop halfway and scrape the dough off the hook and bowl again and continue to knead until the butter is absorbed by the dough. IT WILL HAPPEN, don't worry! DO NOTbe tempted to add any extra flour. You will get a shiny smooth dough that is very elastic. I promise!

1ST PROOFING:

• Place this dough in a lightly oiled large bowl, cover it with a clean and damp tea cloth or plastic wrap and let it rise at a warm place for about 1 hour. It may not double in size, but it will puff up some for sure.

SHAPING:

• Punch the dough down, divide into 8 balls. Cover these doughs loosely with a plastic wrap and let them rest for 15 minutes. Make sure you don't skip this part of resing the dough before shaping
• Flatten one dough and roll into about 4-5-inch circle. Place one filling ball in the middle. Gather the edge of the dough to enclose and pinch to seal the bun. Place the seam side down on a baking pan lined with parchment paper and repeat with the rest of the dough. Cover with a plastic wrap or a clean kitchen towel

2ND PROOFING:

• Let the dough proof again for another 40 minutes or until they fill up the loaf pan. Brush the top of the dough with egg wash
• Sprinkle with some white sesame seeds or other seeds of your choice if you like

BAKING:

• Preheat oven to 350 F and pop it into the oven (3rd rack from the top) and let it bake for the next 20-30 minutes depending on the oven, mine took 20 minutes. It will be golden brown on top. Remove from the oven and let it cool down in the pan for about 5 minutes and then transfer to cooling rack to let them cool down completely

STORING:

• Leftover buns can be refrigerated for up to one week

REHEATING:

• Wrap the buns in aluminum foil and reheat in oven or toaster oven or air fryer at 350F for about 10 minutes to warm up, or simply warm it in the microwave oven for about 1 minute or so

Tried this recipe? I would love to see it!Tag @WhatToCookToday and hashtag #WhatToCookToday

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Soft Fluffy Steamed Custard Buns (Nai Wong Bao)