There's a few variations on butter icing, and it all depends on your taste. I generally start with 1:1 for butter and icing, and you can modify that as you want. Some people also add a splash of milk - I do that sometimes but normally I like to save the milk for the cup of tea I'll invariably be having with my freshly-baked goodies :)
For 18 large cupcakes or one standard-size cake
100g unsalted butter
100g icing sugar
1. Combine until smooth.
SERIOUSLY, that's it. Of course, you normally want to flavour it or colour it or maybe even both (LOOK OUT). If so, once its combined, you need to add in your flavouring/colour and then combine it. Here are some suggestions:
- Melt some dark, white or milk chocolate (as you wish). Or combine them!
- Put some cocoa, coffee or Milo into a cup and mix with a little hot water to make a paste
- Put a few drops of flavouring essence into the icing - vanilla or peppermint (in chocolate icing... mmm choc mint) or whatever takes your fancy!
- Mocha icing: Combine cocoa and coffee!
- Put a few drops of food colouring in and combine until you get to the desired colour
- Grate some lemon/lime/orange rind into the icing