I store my cupcakes in a plastic cake box the sponge goes sticky. If i store a cake in a metal tin, the icing goes sticky.
How long do your cakes normally last before the icing goes slightly sticky, or doesn't it?
Feel like however I store my baking something goes wrong! Its frustrating!
AI store mine in cardboard bakery boxes. That is, for the duration of time between finishing making them and giving to the client who ordered them.
I do the same thing. I have gotten sticky cakes from them being under a dome before frosting them but never sticky icing.