Preheat oven to 180 Degree C | 350 Degree F.
Take individual bake and serve muffin cups and arrange it in a baking tray. Alternatively you could use muffin trays. In that case line it with cupcake liners.
Take brown sugar, water, raisins, butter, rum in a sauce pan. Mix well.
Place the sauce pan on heat and cook till it comes to a boil. Once it starts to boil, reduce the flame and cook for 3 mins.
Take the sauce pan from the heat and set aside to cool for 15 mins.
Mean while mix together, flour, spice powders, baking soda, salt in a bowl.
Once the raisin mixture cools a little, add the flour mixture into the raisin butter and fold gently, Don't over mix.
Now use a ice cream scoop to divide the batter between the muffin cases.
Pop this into the oven and bake for 20 to 25 mins until the cakes are baked.
Remove the tray from the oven and leave to cool for 10 mins