This is for all the American BC experts out there:
I have noticed that confectioners sugar and powdered sugar are used interchangeably here. Do one or both kinds (as sold in the US) contain cornstarch also? Does anyone use pure powdered sugar?
In Australia, powdered icing sugar is 100% sugar while what we call "Icing Mixture" has cornstarch added. Wondering if I cannot reproduce American buttercreams because the sugar I am using does not contain cornstarch.
Our powdered sugar and confectioner's sugar are both names for the same thing and it does contain cornstarch. It sounds like your Icing Mixture might be what you need to try.