Custard Bun Recipe

Warm the milk and melt butter

Warm the milk until it's about 105–110°F (lukewarm). Add the unsalted butter to the warm milk to soften/melt. Let cool slightly if too hot.

Combine dry ingredients

In a large mixing bowl or the bowl of a stand mixer, whisk together the all-purpose flour, instant yeast, sugar, and salt until evenly distributed.

Mix wet and dry

Add the lukewarm milk/butter mixture, the large egg, and the vegetable oil to the dry ingredients. Mix with a dough hook (or wooden spoon) until a rough dough forms.

Knead the dough

Knead on medium speed for 6–8 minutes until the dough is smooth, elastic, and slightly tacky. If kneading by hand, knead on a floured surface for about 10 minutes, adding up to 1–2 tbsp flour only if dough is excessively sticky.

First rise

Shape dough into a ball, place in a lightly oiled bowl, cover with plastic wrap or a damp towel, and let rise in a warm draft-free place until doubled in size, about 60–75 minutes.

Deflate and divide

Punch down the risen dough to release air. Turn out onto a lightly floured surface and divide into 12 equal pieces (each about 70–80 g). Cover pieces with a towel and let rest 10 minutes to relax the gluten.

Shape buns

Flatten each piece into a 4-inch round disk. Spoon about 1½–2 tbsp of cooled custard (see Custard Filling section) into the center of each disk. Gather the edges up and pinch to seal, forming a smooth bun with the seam at the bottom. Roll gently to smooth the top and place seam-side down on a parchment-lined baking sheet, spacing 1–1½ inches apart.

Second rise

Cover the shaped buns loosely with plastic wrap or a lightly damp towel and let rise until puffy and nearly doubled, about 35–45 minutes.

Heat milk

In a medium saucepan, warm 1.5 cups whole milk over medium heat until it just begins to steam and small bubbles form around the edges (do not boil). Remove from heat.

Whisk yolks, sugar, and cornstarch

In a bowl, whisk together the 3 egg yolks, 1 cup granulated sugar, and 3 tbsp cornstarch until smooth and pale.

Temper eggs

Slowly pour about 1/3 of the hot milk into the yolk mixture in a thin stream while whisking constantly to temper the yolks. Then pour the tempered yolk mixture back into the saucepan with the remaining milk, whisking to combine.

Cook until thickened

Return the saucepan to medium-low heat and cook, whisking constantly, until the mixture thickens and comes to a gentle boil (about 2–4 minutes). Once thick, cook for an additional 30–60 seconds while stirring to remove any starchy taste.

Finish the pastry cream

Remove from heat and whisk in 2 tbsp unsalted butter, 1 tsp vanilla extract, and a pinch of salt until smooth. Transfer the pastry cream to a shallow bowl, press plastic wrap directly onto the surface to prevent a skin, and chill in the refrigerator until fully cooled, at least 1 hour.

Egg wash and optional sugar

When buns have completed the second rise and the pastry cream is cooled, brush the top of each bun lightly with the egg wash (beat 1 egg with 1 tbsp water). If desired, sprinkle a small pinch of granulated sugar on top of each bun immediately after brushing.

Bake

Preheat oven to 350°F (175°C). Bake the buns on the middle rack for 15–18 minutes, or until they are golden brown on top and sound hollow when tapped gently. Baking time may vary slightly depending on oven and bun size.

Cool

Remove buns from oven and transfer to a wire rack. Let cool to warm or room temperature. If desired, brush again lightly with melted butter for shine once slightly cooled.