1 For the cupcakes: heat the oven to 180°C (160° fan) 350°F gas 4. Line a 12 hole bun tin with paper cases.
2 Cream the butter and the sugar together until light and fluffy. Add the vanilla, followed by the eggs.
3 Slowly fold in the flour until combined and spoon the mixture into the paper cases.
4 Bake for 10-15 minutes until risen and springy to the touch. Remove the cakes from the tin and cool on a wire rack.
5 For the buttercream: beat the butter until soft and creamy. Sift in the icing sugar and beat well. Gradually beat in sufficient orange juice to give a soft spreading consistency. Stir in the zest and a few drops of orange colouring if using.
6 Spoon the buttercream thickly on top of each cake. Place a jelly starfish in the centre of each cake and sprinkle with sugar crystals.