The last couple cakes I have done has had an area in the icing that bulges. It is not filling, just air. I can push it back against the cake and it's fine. I just don't know what is causing this. Anyone know what I am doing that causes this? Thanks for any input!

Do you refrigerate your cakes before icing them? I only experience that problem during the summer when I fridge cakes and then use an American (crusting) buttercream. It has something to do with the condensation as the cake comes back down to room temperature.

If I don't refrigerate my cakes then I don't have that issue. Therefore I try to stay away from perishable fillings.

Annie