I stumbled upon this quiet and good looking Cafe completely accidentally this week. I was looking for a quiet place to spend one hour, not necessarily a classical bakery, but not a restaurant or a fast-food or anything doing with food, either. I didn't realized from the very beginning what's the main language of this place, but while waiting for my good looking - and good tasting too - cookie, I saw a couple of Polish magazines, among the Spiegel and other local daily newspapers. The lady who served me was speaking Polish (with his colleague, it's how I found out), the sugar was Polish and there were some announcements in Polish. Most probably it is a market for this group, as in the this part, at the border between Charlottenburg and Hallensee I hear often the Polish language and right around the corner it is a German-Polish school.
At this time of the day - between 11.30 and 12.00, if I remember exactly - the place was almost empty, with an overwhelming majority of lady-clients (me included), some of them looking like very familiar to the place, talking with the Polish lady about Berlinale or the latest evolutions in the 'zu Guttenberg' case.