Take water, butter, sugar and cocoa and bring to the boil in a heavy-based saucepan. Remove from the heat and then gradually add the milk powder stirring all the time. Snap optional ingredients if you like them in your home-made chocolate. Pour the chocolate into a mould and leave to rest in the fridge for a few hours. After this time, remove from the mould, divide into equal parts and pack in cellophane. The gift is ready!