Heat the oven to 190 degrees Celsius.
Take a bowl, put in the sugar and butter and beat it together till it is smooth to touch.
Add in the flour and stir it well so that it forms a smooth paste.
Then place this dough on a floured surface and roll it into a layer that is 1 and half cm thick.
Cut this dough into rounds or biscuit shapes and place them on the greased baking tray. Sprinkle caster sugar on top and refrigerate it for 20 minutes.
Bake this for 15-20 minutes, or until they turn a pale golden-brown colour. Once cooked, let it cool on a wired rack.
Serve them warm or store in an air-tight container to last for some days.