Imperial 1 1/2 teaspoons good-quality vinegar 4 tablespoons milk 4 oz flour 1 teaspoon baking powder 1/4 teaspoon bicarbonate of soda pinch of salt 1 teaspoon ground ginger 1/2 teaspoon ground cinnamon 1/4 teaspoon ground allspice 2 oz butter 2 oz brown sugar 1 egg, beaten 6 oz black treacle or molasses