Molasses
Storing molasses in the fridge isn’t necessarily a bad thing, but it certainly is impractical. Since the substance is quite thick, leaving it in the fridge will make it hard and very difficult to use. What you can do instead is store it in a cool and dry place.
Cake
Please, please, PLEASE don’t put cake in the fridge! If you do then you have no right to complain that it’s soggy, or even worse, stale! The only time you should put cake in the fridge is if it is cheesecake or a cake with cream that would spoil at room temperature.