Can I make buttercream icing without icing sugar?

[cupofteaplease]

I've got less than half the icing sugar I need to ice the cake I have made for work tomorrow. I have heaps and heaps of castor sugar though. Is there any way I can make buttercream icing with castor sugar??

Thanks!

I don't think so. Sorry.

If you have a magimix/food processor you can process the caster sugar until it breaks down. It's not exactly like icing sugar but i have done it succesfully.

Thanks, I'll give it a whirl!

Do you have a coffee grinder? If so, you can grind the sugar finer. If you make it with caster sugar, it will be gritty.

Hmm- that didn't work so well. Despite grinding it, it was still gritty...bugger!

What sort of cake is it?

It's a coffee and walnut sponge.

I had the same problem the other day, have you got any drinking chocolate? I used it alongside icing sugar the other day (of course then it was choc butter cream), but it was quite successful.

Prob too late but grind some walnuts and add to the gritty butter cream to disguise the texture.