Cantonese Pineapple Bun (Bo Lo Bao) — Soft Bread Tradition

Ingredients

• For the tangzhong
• 20 g plain flour
• 100 ml water
• For the bread dough
• 300 g plain flour
• 50 g caster sugar
• 5 g instant dried yeast
• 5 g fine salt
• 120 ml whole milk, warm
• 1 egg, beaten
• 40 g unsalted butter, softened, cubed
• For the su pi (cookie topping)
• 60 g vegetable shortening, room temperature
• 80 g icing sugar, sifted
• 1 egg, beaten, divided — part for topping, part for egg wash
• 120 g plain flour, sifted
• To serve
• 80 g salted butter, cold, cut into thick slabs

Method

1. 1
   Make the tangzhong. Whisk 20 g plain flour with 100 ml cold water in a small saucepan until smooth. Set over medium heat and stir constantly until the paste thickens and turns glossy and the mixture reads 65 °C on an instant-read thermometer — it will hold a trail when the spoon is lifted. Remove from heat, press cling film directly onto the surface and cool to room temperature.
2. 2
   Make the dough. Combine 300 g plain flour, caster sugar, yeast and salt in a large bowl. Add the warm milk, beaten egg and cooled tangzhong. Mix to a shaggy dough, then knead — by hand or stand mixer — until smooth, about 8 minutes. Add the softened butter in pieces and continue kneading until the dough is supple, slightly tacky and passes the windowpane test: a small piece stretched between the fingers should thin to a translucent membrane without tearing.
3. 3
   First proof. Shape the dough into a ball, place in a lightly oiled bowl, cover and leave at room temperature until doubled in volume. Knock back, divide into eight equal portions (approximately 80 g each) and roll each into a smooth, taut ball. Arrange on a lined baking sheet with ample spacing, cover loosely and prove again until noticeably puffed, about 30–40 minutes.
4. 4
   Make the su pi. Beat the shortening and icing sugar together briefly — the mixture should be just combined, not aerated. Add half the beaten egg and mix. Add the sifted flour and fold until the dough just comes together into a crumbly, pliable mass. This is where the dish lives or dies: overworking the topping develops gluten, producing an elastic sheet that will not crack in the oven — stop the moment it coheres and handle it minimally.
5. 5
   Apply the topping. Divide the su pi into eight portions. Flatten each between two sheets of cling film into a disc slightly smaller than the proved bun. Peel off the film and drape each disc over the top of a bun, pressing gently so it adheres. Using a sharp knife or lame, score a crosshatch grid — four lines each way — through the topping without cutting into the bread beneath. Brush the scored topping with the remaining beaten egg.
6. 6
   Bake. Preheat the oven to 180 °C. Bake the buns for 12–15 minutes. The topping should be deeply golden and visibly cracked along the scored lines; the bun flanks should be pale and soft to the touch. Do not overbake: the interior must remain pillowy.
7. 7
   Serve. Split each bun horizontally while it is still warm — within 20 minutes of leaving the oven. Insert a thick slab of cold salted butter. The butter should begin to melt against the warm crumb immediately on contact: the savoury-sweet contrast of cold butter and hot bread is the dish.