Preheat the oven to 180°C C/ Gas Mark 4.
Lightly grease and line a 1 lb loaf tin with baking paper.
Sift the flour, salt and cinnamon into a large mixing bowl, add the cubes of butter and rub into the mixture until it resembles fine breadcrumbs.
Add the Whitworths Dark Soft Sugar, raisins and walnuts and mix well.
In another bowl mash the bananas, add the egg and 1 tblsp milk, mix well and pour over the dry mixture. Beat thoroughly until you have a dropping consistency (so that it falls off the spoon quite easily), add the remaining milk if necessary.
Spoon the mixture into the prepared tin, sprinkle the Whitworths Demerara sugar over the top and bake in a preheated oven for 45-50 minutes, or until a skewer inserted into the cake comes out clean.
