Ingredients

Step by step

1. Make the eggnog first, as it needs to be well chilled. Preheat the oven to 170°C, fan 150°C, gas 3½. Toss the hazelnuts with the oil and roast for 12-15 minutes until they are a deep golden brown and smell nutty. Cool slightly, then add to a liquidiser with the milk. Blend until smooth then pour into a pan and bring almost to the boil. Cover and set aside to infuse for 30 minutes.
2. Strain the mixture through a sieve into a clean pan, discarding the solids. Slowly bring back to the boil. Meanwhile, whisk together the egg yolks and sugar in a bowl until pale. Gradually pour the hot milk onto the egg mixture, whisking constantly until combined. Add a pinch of salt and pour the custard back into the pan. Cook over a medium heat, stirring constantly, until it has thickened enough to coat the back of a wooden spoon.
3. Strain through a fine sieve into a bowl set inside a larger bowl of iced water. Stir until the custard is cool then add the liqueur or brandy. Cover and chill until needed.
4. For the doughnuts, combine 50ml of the milk with the butter in a small saucepan and bring to the boil. When the butter has melted, pour in the remainder of the milk and remove from the heat; the milk should be lukewarm. Whisk in the yeast and 50g of sugar, followed by the egg, and place the mixture in the bowl of a stand mixer fitted with the dough hook (you can knead this by hand if you do not have a hand mixer, but it is quite a sticky dough). Sift in the flour and salt, and, with the mixer running on low speed, allow the mixer to slowly knead the dough. Once all the flour has been incorporated, increase to a medium speed and knead for about 5 minutes, until it is completely smooth. It will be slightly sticky and elastic.
5. Scrape the dough into a lightly oiled bowl, cover and leave somewhere warm for about an hour or until the dough has doubled in size. Turn the dough out onto a floured surface and fold it over on itself a couple of times to knock out the air. Divide into 10 balls and place these on a lightly oiled tray, spaced a good 3cm apart. Loosely drape a sheet of oiled clingfilm over the doughnuts and set aside in a warm place to double in size again – it should only take 30-40 minutes this time.
6. Place 100g of sugar on a large plate. Add oil to a large deep pan until it’s a third-full. Heat to 170°C (or until a piece of bread turns golden in a few seconds). If you have one, keep your thermometer in the pan to help maintain a constant temperature. Fry the doughnuts in three batches until they are golden brown, about 1 minute on each side.
7. As each batch is ready, briefly drain the doughnuts on kitchen paper, then immediately roll in the sugar and set aside. When they are all cool enough to handle, make a small slit in the side of each doughnut with a sharp knife. Spoon the jam into a piping bag (thin down with a little boiling water if it seems too stiff) and pipe in as much jam as you can without it spurting out. Serve the doughnuts still warm, with small glasses of chilled hazelnut eggnog alongside.