Ingredients: 

250g/8oz Butter

1.5-2lb/750g-1kg Icing Sugar (Confectioners sugar)

Method: 
  1. Place the butter about in a bowl, and let it warm up to room temperature so it is soft.
  2. Keep adding the icing sugar and beat with an electric mixer (or a wooden spoon if you don't have one - it's hard work though) until the icing is firm.
  3. Next add any colouring or flavouring that you like to the icing, and about two tablespoons of milk or water to give it a pipeable consistancy.

Buttercream icing is very simple to make and work with, but it can be rather sickly.