2. Cream together the butter and sugar until light, fluffy and pale.
3. Gradually mix in the beaten egg alternating with the flour to stop the mix from curdling. Finally, stir through the vanilla extract and milk.
4. Place 12 paper cupcake cases into a muffin tin and divide the mixture between them.
5. Bake for 15-20 minutes until golden and springy to the touch. Remove from the oven and cool on a wire rack.
6. For the frosting: in a mixing bowl beat the butter with a spoon or spatular until smooth, then start to sift in the icing sugar, stirring regularly. Add the vanilla extract and milk. The frosting should be light and creamy.
7. Mix your green food coloring into the icing to give an even green color.
8. Once the cupcakes are totally cool, pipe the icing onto them starting from the outside of the cake and working into the center to create tall Christmas trees. Decorate with silver balls, stars, then allow to set for at least 30 minutes so that the icing has a slightly crispy finish.
