Chocolate Butter Biscuits Recipe

1. Sift the flour, cocoa powder and salt into a food processor, add the butter and process until the mixture resembles fine breadcrumbs. Add the sugar and pulse briefly, then add the egg yolks and vanilla and process until the mixture just starts to come together. Transfer the dough to a work surface and shape into a disc. Wrap in clingfilm and chill for 30 minutes.
2. Roll out the dough on a lightly floured surface to 5 mm (1/4 inch) thick.
3. Use a 7 cm (3 inch) cookie cutter to stamp out rounds and put them on 3 large, lightly oiled baking sheets. Bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 8-10 minutes until lightly golden around the edges. Leave to cool for 5 minutes on the baking sheets and then transfer to a wire rack to cool.