In the past I have always froze my cakes after filling them and crumb coating with with swiss butter cream. I would then cover them with fondant and stack them (if they were multi-layered and put them in the fridge). Depending on the fridge temperature, this usually caused a lot of sweating. I want to leave the cakes out after they are covered but I'm afraid the soft butter cream underneath will not withstand on its own, and once softened will look bumpy? Is this true? Does anyone else leave there fondant cakes unrefrigerated even if they are filled with butter cream? Any tips or suggestions?