You will see them in the markets and sometimes outside. I eat them with goat cheese (sold outside the Mercado Hidalgo, left side, Thursday and Sunday mornings), oh so good!
Another cheese and fruit snack or dessert I like is fresh cheese (quesofresco) with quince paste (ate de membrillo), available in the Mercado Hidalgo--ask for the stall. A little of this traditional favorite goes a long way. The ate keeps almost forever. Convenient to have on hand for an unexpected guest.