??? have left over from cake balls!
Well I have and they were fine after defrosting.
i have frozen both... tasted great after freezing also.
I freeze them both all the time. just re-whip.
You can freeze both, but bring to room temp before re-whipping. Actually stirring it at room temp works perfectly.
I freeze buttercream too. I put it in a Tupperware container, cover the top tightly with plastic wrap, and put on the lid. It will keep for months in freezer. I try to thaw it in the fridge first before bringing it to room temp on the counter (still in the container). I don't know why - I guess I think that I am minimizing condensation that way, but whether or not I actually am, who knows?