Pineapple Bun (菠萝包 Bo Lo Bao) — Hong Kong Bakery Institution

Ingredients

• For the bun dough
• 300 g plain flour
• 5 g instant dried yeast
• 40 g caster sugar
• 30 g unsalted butter or lard, softened
• 150 ml whole milk or water, lukewarm
• 1 egg, lightly beaten
• 4 g fine salt
• For the topping
• 50 g cake flour, low-protein
• 50 g icing sugar, sifted
• 40 g unsalted butter, cold, cubed
• ½ egg yolk
• ½ tsp vanilla extract
• ¼ tsp baking powder
• To serve
• 1 thick slab cold unsalted butter, per bun, for splitting and inserting

Method

1. 1
   Combine the plain flour, yeast, caster sugar, and salt in a bowl. Add the beaten egg and lukewarm milk or water. Bring together into a shaggy dough, then incorporate the softened butter or lard. Knead until the dough is smooth, soft, and slightly tacky but not sticky — it should pull cleanly from the work surface.
2. 2
   Cover the dough and set aside in a warm place for the first rise. The dough is ready when it has doubled in volume and a finger pressed into its surface leaves an indentation that does not spring back.
3. 3
   While the dough rises, make the topping. Rub the cold cubed butter into the cake flour, icing sugar, and baking powder with fingertips until the mixture resembles coarse crumbs. Add the egg yolk and vanilla extract and press the mixture into a cohesive dough. Do not overwork it. Divide into 8 equal portions, roll each into a ball, then flatten into a disc slightly smaller than the diameter of a bun. Chill the discs until needed. This is where the dish lives or dies: the topping must remain cold and short — if it warms and becomes greasy, it will not crack into the characteristic pineapple-skin pattern during baking.
4. 4
   Knock back the risen dough and divide into 8 equal pieces. Shape each piece into a smooth, taut ball by tucking the seam underneath. Arrange on a lined baking tray with sufficient space for expansion. Lay one chilled topping disc gently over each bun, pressing it lightly to adhere without compressing the bun. Allow to prove for a second rise until noticeably puffed — the buns will look visibly fuller and the topping disc will have spread slightly at its edges.
5. 5
   Bake at 190 °C for 12–15 minutes. The buns are done when the tops are deep golden and the topping has cracked into an irregular, raised pattern that echoes the texture of a pineapple's skin.
6. 6
   Remove from the oven and serve immediately, or split while still warm and insert a thick slab of cold butter so that it melts slightly into the soft crumb. The bun should yield to the touch with a gentle spring — the crust crackles audibly under light pressure.