Yes, Visa Cafe on the Dream and Fantasy on Deck 4 have pastries during the day. Cove Cafe on Deck 11 on Fantasy also do as well as all the fast food places on the pool deck (cookies, bags of chips, fresh fruit, etc).
On the Magic/Wonder the fast food places all have some snacks. I have seen bags of chips, cookies, fresh fruit, yogurt parfaits.
Room service is 24/7 but as mentioned some snacks have a charge.
MJ