Here’s a soft, sweet, and iconic Pineapple Bun (Bolo Bao) — a classic Hong Kong bakery treat named for its crackly, sugar-crusted top, which resembles a pineapple.

🍍 Pineapple Bun (Bolo Bao)

🛒 Ingredients (Makes 8 buns)

🍞 Sweet Bun Dough

2 ½ cups (320 g) all-purpose flour
2 ½ tsp instant yeast
¼ cup (50 g) sugar
½ tsp salt
¼ cup (60 ml) warm milk
¼ cup (60 ml) warm water
1 large egg
¼ cup (60 g) unsalted butter, softened

🍍 Sugar Crust Topping

¼ cup (50 g) unsalted butter, softened
¼ cup (50 g) sugar
1 egg yolk
½ cup (65 g) all-purpose flour
¼ tsp baking powder
Optional: a pinch of vanilla extract

👩‍🍳 Instructions

1️⃣ Make the Dough

In a large bowl, combine warm milk, water, yeast, and sugar. Let sit 5 minutes until foamy.
Add flour, salt, and egg; mix into a dough.
Knead in softened butter until smooth and elastic (about 8–10 minutes by hand or 5 minutes with a mixer).
Cover and let rise 1–1.5 hours, until doubled in size.

2️⃣ Make the Sugar Crust

Cream butter and sugar until light.
Add egg yolk and vanilla (if using).
Mix in flour and baking powder until a soft dough forms.
Chill briefly to firm up (10–15 minutes).

3️⃣ Shape the Buns

Punch down dough; divide into 8 portions and shape into smooth balls.
Divide sugar crust dough into 8 portions.
Flatten each sugar dough piece into a disc and gently place over each bun, covering the top.

4️⃣ Proof & Bake

Place buns on a lined baking sheet.
Let proof 20–30 minutes.
Preheat oven to 350°F (175°C).
Bake 15–18 minutes until golden and crackly on top.

5️⃣ Serve

Enjoy warm or at room temperature.
Optional: slice in half and add a pat of butter for a traditional Hong Kong-style treat.

🔥 Tips & Variations

Crispier top: Brush the sugar crust lightly with egg wash before baking.
Sweet filling: Add custard, red bean paste, or chocolate inside the buns.
Flavor twist: Add a pinch of matcha or cocoa to the sugar crust for variety.
Make ahead: Freeze unbaked buns; thaw and bake fresh for soft, fluffy results.

If you want, I can provide a super soft, bakery-style Pineapple Bun recipe with a thick, buttery sugar crust that cracks beautifully on top and melts in your mouth.