Here is a nice and welcoming small café in the heart of charlottenburg. I usually go to the farmers market on wednesdays and have my lunch at the "Baumratterich". The coffee is very good and for lunch you get to pick from a list of fresh made appetizers like paninis and wraps to a (I think daily?) changing main dish.
Usually they have soup which so far has always been vegan and very yummy and other hot meals mostly indian.
I have only had cake there once before because I am usually too full after lunch, but the cakes are housemade and I found my organic "bienenstich" one of the best I have ever eaten before.
The owner is also very nice and always up for a chat.