Cream together the butter and sugar, then add the vanilla. Add the flour and use your hands to bring together into a ball of dough.
Place on a lightly floured work surface and roll out to about 1cm thickness. Cut into shapes, then place on the prepared baking tray and sprinkle with some extra caster sugar.
Bake in the oven for 15 to 20 minutes, or till a pale golden brown. Set aside on a wire rack to cool.