1. Combine flour, yeast, sugar, water, milk, and salt in the bowl of a stand mixer fitted with a dough hook
2. Combine the ingredients on low speed, before increasing the speed to medium-high and kneading for 5 minutes, or until smooth
3. Add the butter and continue to beat for 10 minutes
4. When the dough is smooth and elastic it's ready
5. Transfer the dough to your counter-top, dust lightly with flour, and shape into a ball
6. Place the dough back in a large oiled bowl and cover with cling wrap
7. Place the covered bowl in a warm area for 1-2 hours, or until the dough has doubled in size
8. Dust your worksurface with flour and remove dough from the bowl
9. Release built-up air by flattening the ball and divide it into 6 even portions
10. Roll each portion into a ball and place it on an oven tray lined with baking paper
11. Cover with cling wrap and let it proof for 30 minutes, or until almost doubled in size
12. Heat a heavy bottomed pot of oil to 170C/340F
13. Cut the baking paper that the donuts are sitting on so that each donut is on it's own square of baking paper
14. Carefully pick the donuts up by the corners of the baking paper and place them in the pot of oil, 3 at a time
15. Fry for 2 mins on each side, or until golden brown, then drain on a wire rack or paper towel
16. Repeat with the remaining donuts
17. Cool completely

Custard

1. While the dough is proofing make the custard
2. Combine the egg yolks, sugar, and cornstarch in a large heatproof bowl and whisk to combine
3. Combine the milk and vanilla extract in a small saucepan over medium heat and heat until steaming
4. Remove from the heat and pour into the egg yolk mixture, whisking constantly until smooth
5. Return the mixture to the saucepan and heat over medium-low, whisking constantly until thickened
6. The mixture should be thick enough to draw lines in it
7. Remove the pan from the heat and add the butter, stir until melted
8. Transfer the custard to a bowl and cover with cling wrap, pressing the cling wrap onto the surface of the custard to prevent it from forming a skin
9. Place in the fridge to cool completely

Sugar Syrup

1. Combine the sugar and water in a small saucepan over medium heat and cook until the sugar has melted and slightly thickened
2. Transfer to a small bowl big enough to dip the donuts in

Assembly

1. Transfer the custard into a piping bag fitted with a medium-sized round tip
2. Poke a hole on the side of each donut with a skewer or chopstick, ensuring not to pierce the whole way through
3. Insert the tip of the piping bag into the hole and fill each donut with custard
4. Place the sugar on a small plate
5. Dip one side of the filled donuts into the sugar syrup, then press it, sugar syrup side down, into the sugar
6. Place the donut sugared side up on a heat-proof plate or wire rack
7. Repeat with the remaining donuts
8. Using a blow torch caramelize the sugar to create a 'creme brulee' finish
9. Enjoy!