125g plain flour
50g bread flour
4g active yeast
35g caster sugar
1 tsp salt
50g water, lukewarm
2 small eggs, beaten
125g butter, room temperature, cut to cubes
1 egg, beaten, for brushing
1 tsp vanilla extract
3 egg yolks
25g butter, room temperature, cut to cubes
1. Start with making the brioche dough. Add the flours, yeast, sugar and salt to a mixer bowl and mix together using a dough hook attachment. Add the water and keep mixing on a low speed. Little by little, add the eggs.Turn the speed up to medium and knead for 10 minutes. At this stage the dough should be easily coming of the sides and look stiff. Gradually add the soft butter, piece by piece and continue kneading for another 10 minutes.
2. When the dough becomes shiny and soft, turn the speed up to high and knead for a minute, then turn it down to medium again and continue for another 3 minutes. Transfer the dough into an oiled bowl and cover with a kitchen cloth or cling film. Leave in a warm place to proof for and hour, until it doubles in size.
3. Meanwhile, make the custard. In a mixing bowl, whisk together the egg yolks, sugar and cornflour.
4. Add the milk to a small saucepan and bring to a boil over a low heat. Pour a third of the milk over the egg yolks and whisk into the mixture. Add the remaining milk and whisk until fully combined. Add the egg yolk mixture to the pan and whisking continuously bring all to a gentle simmer. Whisk for 2 minutes. Take the pan off the heat and transfer the custard into a mixing bowl. Add the butter and whisk it in.
5. Leave to cool completely and whisk again to a smooth texture. You can strain the custard through a fine sieve, if there are any lumps.
6. Preheat the oven to 140*C/120*fan. When the dough doubled in size, knead it gently for few seconds and cut into 6-8 equal size balls. Shape into round buns and put on a baking tray lined with baking parchment. Leave for the final proof for another 20 minutes, then brush with the egg and put the tray in the oven.
7. Bake for 5 minutes on 140*C/120*C fan and then turn the heat up to 170*C/150*C fan. Bake for another 15 minutes, until the little buns are golden brown.
8. Remove the tray from the oven and let the buns cool down completely before putting the custard in.
9. Assemble the buns by making a cut in the middle of each but not all the way through. Spoon or pipe the custard into the bun and decorate with the blackberries. You can also pipe the custard into each bun, like you would with doughnuts. If you decide to do so, you can fill the buns when they are still slightly warm.