Preheat oven to 170°C (325°F, Gas Mark 3).

Grease and line a 20cm (8 inch) round cake tin with greaseproof paper.

Cream together the butter and dark brown sugar in a large bowl until light and fluffy.

Beat in the egg until well combined.

Stir in the black treacle.

In a separate bowl, sift together the self-raising flour, ground ginger, mixed spice, and salt.

Gradually add the dry ingredients to the creamed mixture, stirring until just combined.

Dissolve the bicarbonate of soda in the lowfat milk.

Pour the milk mixture into the cake batter and stir well.

Fold in the dry mixed fruit until evenly distributed.

Pour the batter into the prepared cake tin.

Bake in the preheated oven for 60 minutes, or until a skewer inserted into the center comes out clean.

Let the cake cool in the tin for 10 minutes before transferring it to a wire rack to cool completely.