Preheat oven to 180ºC . Grease some cookie sheets. Set aside. Mix together the flour, oatmeal, bran, sugar & spices in a bowl. Rub in the margarine until the mixture resembles coarse breadcrumbs. Add enough water to make a stiff dough. Roll out the dough on a floured board to a thickness of 1 cm. Cut into rounds, 5 cm to 8 cm across. Place on baking sheets. Bake for 25 minutes. Lift carefully onto a wire rack to cool.