Basic white icing?

[Kentishwoman]

What the best way of making basic white icing to go on top of muffins/cup cakes? All my cake recipes do a fancy icing with mascarpone or whipped cream or some such nonsense. I just want the kind of thing you get on top of an iced bun. Is it just icing sugar and water, or is there butter (or anything else) in it? (NB it needs to be able to sit around for a good couple of days without going in the fridge.) Thanks!

Icing suger and water thats it - but make it quite thick like exta thick double cream and blob it on and spread it around - it will even and smooth itself out.

If you make it too thin it will run off and wont set.

"Basic icing" would be icing sugar with a little cold water. You can use lemon juice instead if you like. Add the water to the sugar very carefully as it is easy to make the mix too thin.
For cup cakes I generally use a butter cream - icing sugar with half the weight of softened butter plus any flavourings.

Thanks! Lilymaid, would I need to fridge it if it had butter in it?