Short answer
A custard bun is a soft Chinese bakery bun filled with sweet, smooth egg custard. It comes baked, with a golden shell, or steamed, with a white pillowy shell, and it differs from a cream bun, which holds whipped cream.
A custard bun is a soft bun filled with a smooth, sweet egg custard, found in Chinese bakeries and dim sum restaurants. Baked versions have a golden shell, steamed versions are white and pillowy, and the filling is cooked custard, which sets it apart from a bun filled with whipped cream.
What is a custard bun?
A custard bun is a sweet bun with a cooked egg custard filling, usually made from egg yolk, sugar, milk and a thickener such as flour, cornstarch or custard powder. It is a staple of Cantonese and Hong Kong style bakeries.
The same idea appears in several forms. The baked kind is often called nai wong bao in Cantonese bakery language, written in several romanizations, while the steamed kind at dim sum restaurants is a close relative. Liu sha bao, a steamed bun with a runny salted egg yolk custard, is a different filling and is not the same as the sweet bakery custard bun. This guide covers the common sweet bakery bun. English names include custard bun, custard cream bun, egg custard bun and, in some cases, yolk bun.
What is inside a custard bun?
The inside of a custard bun is a thick, spoonable cooked custard, pale yellow, sweet and milky, wrapped in a soft wheat bun.
| Part | Common ingredients | What it does |
|---|---|---|
| Bun | Flour, milk, sugar, egg, yeast, butter | Soft, tender, slightly sweet shell |
| Filling | Egg yolk, milk, sugar, flour or cornstarch, butter | Smooth, sweet, set custard |
| Topping (optional) | Egg wash, sesame, or a sugar crust | Color or crunch |
The filling is cooked on the stove until it thickens, cooled, then spooned or piped into the dough. The thickener keeps it from running out in the oven.
What is the difference between a custard bun and a cream bun?
The difference is the filling. A custard bun holds a cooked egg custard that is thick and warm-tasting, while a cream bun holds whipped cream or buttercream that is lighter and cold.
| Feature | Custard bun | Cream bun |
|---|---|---|
| Filling | Cooked egg custard | Whipped cream or buttercream |
| Color | Pale to deep yellow | White or ivory |
| Texture | Thick, smooth, pudding-like | Airy, fluffy or dense and buttery |
| Temperature | Warm or room temperature | Often chilled |
| Shelf life | Short, egg and milk based | Short, refrigerate |
In some bakeries the labels overlap, so color is a good clue: yellow points to custard, white to cream.
Is a custard bun baked or steamed?
A custard bun can be baked or steamed, and the two behave differently. Baked buns have a golden, slightly crisp skin, while steamed buns have a white, soft, springy skin.
- Baked: shaped, proofed, brushed with egg wash and baked until golden. Common in bakery cases.
- Steamed: wrapped, proofed and cooked in a steamer. Common in dim sum restaurants and sold hot.
- Fried: less common, with a crisp outside and a hot filling.
Both forms use a similar enriched dough. The method changes only the texture of the shell, not the idea of the filling.
How do you make a custard bun at home?
To make a custard bun, cook a thick custard, chill it, wrap it in sweet yeast dough, proof the buns and bake or steam them. Here is the short method.
- Whisk egg yolks, sugar, milk and a thickener in a pan over low heat until the mixture is thick and glossy, then cool it completely.
- Make a soft yeast dough with flour, milk, sugar, egg, yeast and butter, and let it rise until doubled.
- Divide the dough, flatten each piece and place a spoonful of chilled custard in the center.
- Pinch the dough closed, seam side down, and let the buns rest until puffy.
- Brush with egg wash and bake at about 350 degrees Fahrenheit for 12 to 15 minutes, or steam for about 12 minutes.
The custard must be cold and thick before filling. Warm or thin custard leaks and makes the seams burst.
How do you eat a custard bun?
A custard bun is eaten by hand, in bites that reach the filling, often with tea or coffee. Warm buns are best bitten gently from one side because the custard holds heat.
- As a morning pastry or afternoon snack.
- Warmed for 20 to 30 seconds in a microwave, or longer in a low oven so the shell stays soft.
- Without dipping, because the bun is already sweet.
Eat custard buns the same day when possible. The filling contains egg and milk, so refrigerate leftovers and warm them before eating.
What is a custard polo bun?
A custard polo bun is a pineapple-style bun with custard inside, so it has a crumbly sugar crust on top and a soft custard center. The name polo comes from the Cantonese word for the pineapple-style crust.
Compared with a plain custard bun, the polo version has more texture: crisp crust, soft bread and smooth filling in one bite. It is one of the more popular combinations in Hong Kong style bakeries.
What problems affect a custard bun, and how do bakers avoid them?
A custard bun can fail in three ways: the filling leaks, the shell dries out or the custard turns grainy. Each has a simple cause that home bakers and bakeries both manage.
- Leaking filling: the custard was too thin or warm, or the seam was not pinched shut. Cook the custard until it holds a ribbon, chill it fully and seal with a dry fingertip.
- Dry shell: the buns were baked too long or the dough had too little milk and butter. Bake only until golden.
- Grainy custard: the eggs cooked too fast. Keep the heat low and whisk constantly, then strain if needed.
- Soggy bottoms: steam collected under the buns. Cool them on a rack, not on the tray.
When buying from a bakery, a bun with an intact seam and an even golden color is usually the safer pick. A bun that feels heavy for its size often holds plenty of filling.
Are custard buns on the Napoleon Super Bakery menu?
Yes. The menu recorded for this guide lists a Custard bun, a soft bun with a sweet custard filling, and a Custard polo bun, a pineapple-topped bun with custard inside. Prices are not published for either item.
Listings for Napoleon Super Bakery on Wanderlog name custard buns among the popular items. The bakery is at 810 Franklin St in Oakland Chinatown. The menu page lists everything recorded, and the hours and location page covers times and directions. A Wanderlog listing says the bakery is cash only, which is worth confirming by phone. This guide is independent and takes no orders.
Common questions
Is a custard bun the same as a cream bun?
No. A custard bun holds a cooked egg custard, thick and smooth, while a cream bun holds whipped or buttercream filling, lighter and often cooler. Bakeries sometimes label them loosely, so ask or look at the color of the filling.
What does the filling of a custard bun taste like?
Sweet, milky and gently eggy, with a smooth texture closer to a thick pudding than a runny sauce. Some versions are yellow from egg yolk and custard powder, and a few add coconut.
Are custard buns served hot or cold?
Both. Baked custard buns are common at room temperature, while steamed custard buns are often served hot. Hot filling can be very warm, so bite carefully. Reheat gently so the filling does not split.
How is a custard bun different from a custard polo bun?
A custard polo bun adds the crumbly sugar crust of a pineapple bun on top of the custard-filled bun. The bread and filling are similar, but the topping changes texture and makes the bun look golden and cracked.
How long do custard buns keep?
Custard buns are best the same day. Because the filling contains egg and milk, they should be refrigerated if kept longer, for no more than a day or two, and reheated until warm before eating.
Planning a visit? Start with Napoleon Bakery Oakland: address, opening hours, menu and directions in one place.
This article is general information from an independent guide, not from Napoleon Super Bakery itself. For the store’s current details see hours and location.