I'm making a wedding cake for a friend, and she is really hoping to incorporate a fruit (pineapple) filling in some form. The cake will be outside for a full day in the spring, so perishable fillings (curds, etc.) are out of the question. The tricky thing is, I've been reading a lot of mixed things about whether homemade (or even storebought) fruit preserves or jam would be safe to use here. Some say these are safe in a cake left at room temp for a day or two, while others say jams cannot ever be left out at room temp for over two hours. If the jam is acidic (pH below 4.6) and contains enough sugar (I'm thinking a 1:1 ratio?), do you think it would be safe in a cake left out all day? Or, alternatively, do you know of any food safety resources I can use to find out? Thanks folks!