Hi Laura, Ganached cake can stay out of the fridge 3-4 days (in room temperature), but it’s depend of your filling of the cake…I always put on the fridge all my cake because we are here (Italy) always use fresh cream as a filling for the cake. Until now I don’t find disadvantage of using chocolate ganache….
You can put ganached cake (chocolate ganache not white choco) around 15-30 min before put the fondant ….it’s depend on your fridge if it’s really cool or not…just check when it set than it’s ready to cover with fondant. Hope I can help you :)
