Tiramisu Donuts with White Chocolate Filling

For the brioche:

1. Place the milk in a medium sized saucepan set over medium-low heat. Heat until the milk is lukewarm in temperature. Remove from the heat and use a fork to stir in the yeast then leave the mixture to sit and prove for 5 minutes until the yeast has dissolved.
2. Meanwhile, place the flour, sugar and salt in the bowl of a stand mixer fitted with the dough hook attachment. Mix on low speed to evenly distribute the ingredients.
3. Add the milk and yeast mixture into the bowl of the stand mixer. Increase the speed to medium and mix to roughly combine, 1 minute. Add in the egg and egg yolk and continue to mix for a further 4 minutes to form a smooth dough ball. The dough will look quite rough at first but will smooth as it continue to knead. Add in the vanilla and mix to combine.
4. Add in the butter, a tablespoon at a time, until it is all incorporated. Increase the speed to medium-high and continue to knead until the dough is very smooth and velvety, about 6 more minutes.Pause mixing to scrape down the bottom and sides of the bowl as needed.
5. Turn the dough out and onto a lightly floured work surface. Pat it down slightly. Fold the left side over the right, the right side over the left, the top to the bottom and the bottom to the top. The dough should resemble an ‘envelope package’ with the seam facing the top. Place the dough seam side down in a large lightly greased bowl and set it in a warm place to rise until doubled in size, 1 hour.
6. When the dough has risen, knock it back down and transfer it back to the lightly floured work surface. Repeat the folding process as above then set the dough back in the bowl. Cover the bowl with plastic wrap and refrigerate for at least 2 hours, preferably overnight

For the white chocolate and tiramisu créme patissiere:

1. Whilst the dough is chilling, you can prepare the white chocolate and tiramisu créme patissiere. Place the milk and roughly crushed coffee beans in a large saucepan. Use a sharp knife to horizontally split open the vanilla bean pod. Scrape the seeds into the saucepan then add in the split pod too. Heat the mixture over medium heat until it reaches a light rolling boil. Remove from the heat and let the mixture sit to infuse for 30 minutes.
2. With an electric hand whisk, whisk the yolks, sugar and cornflour in a medium sized bowl until pale, fluffy and leave the mixture leaves a trail when the whisk is gently lifted, about 3 minutes. Set the bowl aside.
3. Strain the milk mixture through a fine mesh sieve and discard the crushed coffee beans and vanilla bean pod. Re-weight the milk. The coffee beans would have absorbed about ¼ of the milk so add enough extra milk so that it reaches 500 millilitres (16.9 fluid ounces) again. Return it to the saucepan and heat, over medium-low, until it is just beginning to simmer.
4. Remove the mixture from the heat and ladle in a generous scoop of the milk into the egg yolk bowl. Whisk it vigorously to combine and acclimatise the eggs then return the mixture back into the saucepan with the milk. Set it back over the heat. Whisk often, concentrating whisking around the edges of the pan until the mixture is thick enough to coat the back of a spoon and leaves a trail.
5. Remove from the heat and whisk in the white chocolate until smooth and melted then whisk in the coffee liqueur or marsala.
6. Transfer the créme patissiere to a large bowl and cover the surface closely with a piece of plastic wrap. Refrigerate until cold, 3 hours.
7. Once cold, fold in the mascarpone and the finely chopped dark chocolate. Transfer the mixture to a piping bag fitted with a 2 centimetre (.8 inch) round nozzle. Refrigerate until required.
8. To make the doughnuts and coffee and vanilla bean sugar:
9. When you are ready to make the doughnuts, transfer the chilled dough onto a lightly floured work surface. Roll it out with a lightly floured rolling pin until it is about 28 centimetres (11 inches) wide and about .6 centimetres (1/4 inch) thick.
10. Using a 7.5 centimetre (3 inch) circular cutter cut out 8 dough circles. Carefully transfer them to a parchment lined baking tray or slipmat. Then, using a 2.5 centimetre (1 inch) circular cutter, cut out as many mini circles as you can with the scraps. Re-roll the remaining scraps by gently kneading the dough together to cut out more mini circles. Transfer them to the tray and cover it with a piece of plastic wrap. Place in a warm place to prove for a further 1 hour.
11. Meanwhile, make the coffee and vanilla bean sugar by blitzing the sugar, espresso powder and vanilla bean seeds in the bowl of a small food processor until fragrant and the espresso is evenly distributed throughout. Alternately, you can grind the ingredients together in a mortar and pestle. Set the sugar aside in a medium sized bowl.
12. When the doughnuts have risen, pour the oil into a large and deep saucepan. Heat, over a medium-low temperature until it reaches 175 C (350 F). Watch the temperature closely! The temperature should quicken as it nears close to 175C (350 F).
13. Gently pick a doughnut up and place it in the oil. Fry on one side for 2 minutes then flip with a handheld metal strainer and fry on the other side for a further 1 minute or until golden brown all over. Remove the doughnut and let it cool on a kitchen paper towel lined baking tray for about 5 minutes before transferring it into the bowl of sugar and generously coating it. Repeat with the remaining doughnuts, making sure not to fry more than 3 to 4 at a time.
14. When you are ready to fill the doughnuts, use a sharp knife to insert a little hole into the sides of each. Insert the piping nozzle into the hole and pipe in as much of the white chocolate and tiramisu créme patissiere as the doughnut allow, letting some of it ooze out of the sides. Repeat with the remaining doughnuts.