Hi,
My hubby has a slightly sweet tooth, so I make him loads of experimental cakes.
My cakes are sugar free though. I don't use Spenda or any other sweeteners because my hubby (type 1) has strange reactions to them.
The best results I've had have been with fruit instead of sugar. So if I'm making a date and walnut cake for example, I'd use an egg, w/m flour, ground almonds, walnuts (whole and crushed) soaked and blended dates, a few spices and a banana - stick it all in a blender and give it a good mix and them into the oven until its cooked. For an icing, well the best one I've found is simply melted high % chocolate (low in carbs) poured over the cake and left to set. Can't be beaten!!
I use most fruits instead of sugar although banana's are the best. Dried fruits are also good, just soak them in warm water to rehydrate then put in the blender to make mushy. Prunes are extremely sweet and so are dates! They add just enough sweetness for a cake.
Just experiement! Nic.