Custard-filled bao buns

Method

1. Step 1

   Mix the plain flour, sugar and instant yeast powder together in a large deep bowl. Prepare your warm water in the microwave for 20-40 seconds (the water should be uncomfortably warm to touch but not so hot that you cannot dip your finger in it). Gradually add the warm water, ensuring it is fully incorporated before adding more. Knead until you have a smooth dough that does not stick excessively to your hands. The dough is ready to proof when it is soft and malleable, lighter in colour and does not cling to the palms of your hands too much.

   If the dough is too sticky, cover and let it rest for 10 minutes to allow the water to be absorbed by the flour.

   If you are using electric dough hooks:

   Pour in the water in 3 parts adjusting the speed of the electric mixer with each part. Set on a low speed and knead until a shaggy dough begins to form. Scrape down sides until all the dry ingredients are incorporated. Then set on a medium speed and knead until everything is incorporated into a stickier dough ball. Finally, set on a medium-high speed and knead until a smooth and malleable dough forms.

2. Step 2

   Form a dough ball with a smooth and taught skin by picking up the dough, pulling the dough back on itself and tucking the ends into the middle of the ball, like breaking a book and folding the covers back on itself. Rotate the dough ball and continue to fold it back on itself until a smooth and taut dough ball forms. Place the dough ball on a flat surface, no flour required, with the smooth side up. Cover the dough ball with your hand, like holding a computer mouse, and slowly drag the dough ball towards yourself. Feel the friction between the dough and surface create a smooth and sealed base.

   Coat the sides of a bowl with a teaspoon of oil to prevent the dough from sticking to the walls when rising. Turn the dough ball in the oiled bowl so that the dough is covered in a light shine of oil. Cover the bowl in cling film, place in a warm place and let the dough proof (rise) until it has doubled in size (for approximately 60 to 90 minutes).

3. Step 3

   Whisk the eggs, sugar and cornflour in a small bowl until they become a combined paste. On low heat, in a small saucepan, mix the double cream and vanilla extract until well incorporated. Bring the vanilla cream to a gentle simmer, stirring occasionally. Take off the heat when small bubbles begin to form at the edge and centre of the saucepan. Whisking constantly, gradually pour the vanilla cream from the saucepan into the bowl of eggs, sugar and cornflour. Pour the mixture back into the saucepan and cook over a low heat (without stirring) until a thin skin forms on the base of the saucepan. You can swirl the saucepan to reveal the base to check if the skin has formed. Using a spatula, scrape this skin and stir into the custard. Continue this process until it has thickened (3-4 minutes). Take the pan off the heat when you can draw a line with your spatula in the custard and it starts to leave a trail but still knits back together. Continue to draw lines in the custard until the custard lines struggle to knit back together. Transfer the custard to a bowl or lipped plate and cover in cling film, ensuring the plastic touches the custard to prevent a skin from forming. Refrigerate until the custard is cold and solid enough to scoop (roughly 2 hours) or leave overnight in the fridge.

4. Step 4

   Once the dough has doubled in size, punch down the dough. Weigh the dough and divide into 12 similarly-weighted pieces. Recreate the dough ball shape for each piece using the techniques in step 2. Place all 12 dough balls onto an oiled plate and cover lightly with cling film. Leave to proof again for another 30 minutes.

   Divide your custard filling into 12 pieces (approximately 1 teaspoon per bun). Cover the shaped and divided dough and custard while you prepare each bun. Roll out each dough ball in 10 cm rounds so that the circles are thicker in the centre and thinner at the edges. You might find this easier with a sheet of oiled cling film underneath and another on top of the dough when you roll it. If you find the dough is snapping back into its original shape, it is too cold or has been overworked. Cover the dough and let it rest for 15-30 minutes to relax at room temperature (place the divided custard back into the fridge in the meantime). The dough should be relaxed for optimal ease of assembly.

   Oil your hands and form a closed circle with your hand. Place the dough disk over the circle, letting the dough sag into the gap. Pleat two folds at the base of the dough disk, forming a trumpet lily shape. Place a teaspoon of custard in the centre and then stretch and pinch the dough over the custard filling until completely sealed. Place the dough pleat side down on the work surface and seal completely using the dragging technique found in step 2. Place in a cupcake case or 10cm parchment paper. Repeat the process for all 12 buns before covering the formed buns and leaving to proof a second time for 30 minutes in a warm place until puffy.

5. Step 5

   Set up your steamer and bring the water to a boil. Place the proved buns about 2 inches apart (if in cupcake cases they can be touching). Steam the buns for 10 minutes over the boiling water. Do not open the lid during the steaming process. At 10 minutes, turn off the heat but do not open the lid for a further 5 minutes. Remove the buns from the steamer and allow to cool for 3-5 minutes before serving.