Add 120 grams unsalted, cubed butter and pulse until the mixture starts to clump together.

Press the crumbs lightly into a dough and roll out thickly on a cornflour-dusted board. 

Press or cut into shapes, transfer to a non-stick baking tray or a tray lined with baking paper, and bke for 12-14 minutes. Allow to cool on the tray and sprinkle with caster sugar to serve.