Courgette or carrot cake
One of my favourite cakes when there is a celebration to be organised is carrot or courgette* cake.
As cakes go it's reasonably 'healthy' as you can use light olive oil or sunflower oil instead of butter, you can use brown sugar and obviously it has quite a bit of grated carrot or courgette (as you prefer) too.
There is also an option for extra special days when I make a chocolate icing with dark chocolate and butter obviously making it much richer but scrumptious at the same time.
If you are interested in trying out this recipe, check Jamie Oliver's version.