Preheat the oven to 190 C / 170 C fan / Gas 5. Grease a loaf tin and line with baking parchment.
Sieve the flour with all the other dry ingredients into a bowl.
Put the butter/margarine into a cup and fill with boiling water until melted and add to the dry ingredients. Now add the egg, and the syrup, treacle and sugar. Mix together thoroughly until smooth. Add the raisins and stir in. Transfer the mixture to the prepared cake tin.
Bake in the preheated oven for 1 hour or until a skewer inserted into the centre comes out clean. If the top is going dark don't worry as you are going to ice it.
Once cooled make up a thick icing as desired and cover thickly all over the top leave to set properly then take a slice with a coffee and enjoy!