Grease and line 2 loaf tins, each with a base measurement of approximately 20 x 8 cm (8 x 3¼ inches), with nonstick baking paper.
Sift the flour and bicarbonate of soda into a bowl. Beat together the milk and egg. Put the sugar, treacle and butter in a saucepan and heat gently until the butter melts and the sugar dissolves. Remove from the heat and add to the milk mixture along with the chopped ginger. Add to the dry ingredients. Using a large, metal spoon, stir well until combined. Turn into the tins and level the surface.
Bake in a preheated oven, 160°C (325°F), Gas Mark 3, for 30 minutes, or until just firm to the touch and a skewer inserted in the centre comes out clean. Leave to cool in the tins, then transfer to a wire rack.
Pour the pomegranate juice into a saucepan and bring to the boil, then boil for about 15 minutes until thick and syrupy and reduced to about 3 tablespoons. Stir in the honey. Halve the pomegranate and push the halves inside out to release the fleshy seeds, discarding any white membrane, and scatter over the cakes. Drizzle with the syrup and cut into small squares to serve.