240g (8 ½ oz) butter, at room temperature

120g (4 1⁄4 oz/1 cup) confectioners’ sugar

360g (12 ¾ oz/2 ¾ cups) all-purpose flour

1 vanilla pod, seeds scraped out

½ tsp flaky sea salt

2 tbsp sumac

2 tbsp granulated sugar

Use a food processor or an electric mixer with a paddle attachment to work the butter, icing sugar, flour, vanilla seeds and salt until the mixture just forms a ball of dough. It takes a while to come together, so don’t lose faith.

Once it has formed, turn the dough out onto the work surface. Divide into two pieces and shape each one into a log – I prefer to make it rectangular but it is tasty in any shape.

Mix the sumac and sugar on the work surface. Roll the log in the sumac-sugar to coat all over

place in the fridge to set for at least 1 hour (or freeze it until you want to bake them).

Heat your oven to 190°C/170°C fan/375°F/gas mark 5. Line two baking trays with baking paper

Use a sharp knife to cut each log into 12–14 slices and place them flat on the trays.

Bake for 10–12 minutes until light golden, then remove from the oven.

Leave to cool on the tray before eating.