Zamane Kahvesi is a very unique concept combining a 'pastane' (patisserie), cafeteria, and bistro (however without alcoholic beverages). Currently the have to venues, one on Valikonağı Caddesi in Nisantasi, the other one on Bağdat Caddesi. Their tastiest selections on the menu are predominantly traditionally Turkish pasta dishes, such as Köy Eriştesi and Mantı. In case you are there only for cafe and desserts, you will probably find specialty cakes such as 'Egpa' delicious.
Their venue on Bağdat Caddesi is also a very suitable for children's special occasions, since in such a case the entire second floor of Zamane Kahvesi is provided for the party!
I would definitely recommend Zamane Kahvesi for breakfast, lunch, or desserts during any time of the day.