Heat the oven to 180C/160C fan/gas 4. Cream together the butter, sugar and vanilla in a bowl until light and fluffy. Sift the flour, cornflour or arrowroot and a pinch of salt into the bowl, then fold into the butter mixture until it forms a soft dough.

Roll out the dough on a lightly floured worksurface until roughly 4mm thick. Cut out the biscuit shapes using a lightly floured 7½cm round cutter. Put the dough rounds on a lined baking tray, about ½ inch apart, then sprinkle with a light dusting of sugar. Bake for 15 mins or until lightly golden. Allow to cool then serve. The shortbread can be stored in an airtight container for up to two weeks.

Alternatively, to make shortbread fingers, press the dough into a lined square tin (we used 23cm x 23cm). Chill for at least 1 hr (or up to a day). When ready, bake for 30 mins until the shortbread is lightly golden and cooked through. Allow to cool for 2-3 mins, then carefully remove from the pan and cut into fingers.