Preheat the oven to 200°C/Fan 180°C/Gas 6 and arrange 24 fairy cake paper cases in two bun tins.
Place all the cake ingredients into a large mixing bowl and beat with an electric mixer until well blended and smooth.
Divide the mixture between the paper cases – leave about 1cm between the mixture and the top of the paper cases. It is important not over fill the cases as you need a little of the rim of the paper case above the level of the cakes when they are baked so that it is easy to ice the top. Bake in the preheated oven for about 15 minutes, or until the cakes are well risen and golden brown.
Lift out and cool on a wire rack. To make the icing, mix the icing sugar with 3–4 tablespoons of water to give a smooth coating consistency. Spoon over the cakes and decorate as liked with edible or icing flowers.