Preheat the oven to 190°C fan. Line a baking tray with baking parchment. Grind the hazelnuts in a food processor until a crumbly texture. Melt the butter in a pan over a low heat. Set aside.

If making the dough by hand, whisk together the sifted flour, baking powder, sugar and a pinch of sea salt ( skip the salt if you prefer a sweeter dough ) in a large mixing bowl. Add the butter and pass the mix through your fingertips lightly, thumbs across fingers, to make breadcrumbs – the aim here is to coat the flour in the butter, not rub it in, so keep your fingers light and fast. This may take 5 mins or so. Alternatively you can use a food processor for this first stage.

Now add the milk and egg, and with well-floured hands bring the mixture together to form a dough. Lightly dust it with flour and shape it into a ball. Wrap the dough in cling film and refrigerate for a minimum of 20 mins. Make an egg wash by whisking together the egg yolk and milk.

Remove the dough from the fridge and gently roll out to 3cm thickness on a lightly floured surface. Cut out rounds using a 6cm cutter and place on your prepared baking tray, leaving a little room for expansion. Brush the tops with a thin layer of egg wash and sprinkle with the ground hazelnuts and some extra brown sugar, if you like.

Bake for 15 mins, or until just lightly browning. Remove from the oven and allow to cool on the tray for 10 mins before transferring to a wire rack to cool completely.