Brown butter jigsaw biscuits

Method

1. Put the butter in a pan and melt gently. When completely melted, turn up the heat and bubble for a couple of minutes until it smells biscuity and turns a deep golden brown colour. Quickly transfer to a cold mixing bowl and leave to cool, then chill until the butter has solidified. Cut into large chunks.
2. Put the flour in a food processor with the butter and a good pinch of salt. Whizz together until the mixture looks like fine breadcrumbs. Whizz in 2 of the egg yolks, then finally the icing sugar, until the dough starts to clump together. Transfer to a lightly floured surface and knead gently a couple of times to bring together. Shape gently into a fat disc, wrap in cling film and chill for 30 minutes to 1 hour.
3. Heat the oven to 180°C/160°C fan/ gas 4. Remove the dough from the fridge. On a lightly floured surface, gently roll out the dough to around the thickness of a £1 coin, then stamp out shapes with your shaped cookie cutter. Transfer the biscuits to baking sheets lined with baking paper, whisk the reserved egg yolk until smooth, then brush each biscuit with it and scatter generously with demerara. Bake for 10-12 minutes until pale golden around the edges and crisp. Cool for 5 minutes on the tray, then transfer to a wire rack and cool completely. If you’re not eating them straightaway, the biscuits will keep in a sealed container for 2-3 days.