Odd question, and one I should know the answer to (my job is to teach cooking!!) but I've just made 2 christmas cakes and as I was putting them in the oven had a sudden memory that you're suppose to cook them seperately. Something about the oven struggling to cook them as there's too much in there. Does anyone know anything about this? They are in the oven now, it's too late! I suppose they might take longer than usual to cook because of this... [hhmm] . I've got an electric fan oven if that helps.