[snugs]

Caster sugar is fine granulated not powdered or confectioners sugar which we call icing sugar.

Either granulated or fine granulated will work though IMHO finer sugar is preferable to very course granulated. The cheaper granulated in Britain tends to have larger particles than the more expensive brands maybe that is the same in the US.

[Fishtalk]

Okay Snugs...gotcha. I used granulated.