Carrot Cake with Maple Syrup Butter Icing

I have to confess I was never a big fan of carrot cake.. until I started using this recipe, which I found in one of my old baking books. The butter icing isn't compulsory but it's amazing; if you can get hold of some maple syrup it really adds a bit of extravagance to the cake. The recipe calls for raisins, which is one of the few foods I strongly dislike, so I omitted them; I've included them in the recipe in case anyone wanting to make this has less strong feelings against them. This was actually a recipe for an average sized cake, but my ongoing obsession with fairy cakes meant I just made them instead!