This is one of the simplest of cake-making techniques, relying on a melted mixture of butter, sugar and treacle for moistness and bicarbonate of soda for lightness. Measure the treacle accurately - too much will result in a heavy cake. The bicarbonate of soda will begin to work as soon as the ingredients are mixed, so work quickly.
Stir butter, sugar and treacle over a low heat with a wooden spoon until just melted. Let cool slightly.
Pour slightly cooled melted mixture into egg and milk, mix well, then start to stir in flour from sides.
Beat with a wooden spoon until the mixture is smooth, with a dropping consistency.