How old is your little one? Do you mean things like "Garden" or prepacked from bakery such as Arome and Maxim's?
I would only give my boy prepacked bread and cake from local bakery shop whatever selling freshly baked products because I want to keep all of his food free from preservative and additive.
Once I was attracted by the packing and outlook for some imported bakering but decided not to get them because it saids on the label that those nice looking stuff contain preservative.
As long as we are aware of the ingredients of food product it is fine to give baby prepacked thing.