Some time ago, a friend took me to a very nice place in Prenzlauer Berg. Close to U Eberswalder Straße, on Oderbergerstr., you can find the small café Kauf Dich Glücklich, kinda means Buy your hapiness.
They serve ice creams, waffles, crepes (but not on week-ends), hot and cold drinks and cocktails. The place is very cosy, the staff extremely friendly. I had a waffle with hot raspberries and ice cream which was excellent. Also had a kind of caipirinha, but with white rhum since they were out of cachaça. It was still quite nice.
Very cool atmosphere, nice music, I really liked this place and will for sure go back.