Preheat oven to 350 deg F.
Butter a 9 inch square pan.
Cream butter and sugar together until pale. Add other ingredients except flour - mix. Add the flour. Mix very gently with a wooden spoon then your hands until you have a smooth dough.
Transfer dough to a floured surface and roll out to 1/2 inch thick. Press riolled dough into pan.
Prick all over with a fork and bake for 20-25 minutes. While still warm sprinkle with sugar.
Cut into 12 pieces.