For the German speakers: "Käsekuchen" (literally "cheesecake") in Germany, Poland and other countries of the region uses Quark, which is untranslateable, but is texture-wise somewhere between light cream cheese and pressed Greek Yogurt. It's not usually referred to as a cheese within Germany any more. So Käsekuchen is a sweet cake that goes well with red jam and fresh cream, or served with coffee.
Käsekuchen in Switzerland (again, "cheesecake") is a pie with a filling based on cream and grated hard cheese. If you want the sweet German cake, you have to order "Cheesecake" (using the English word!), not "Käsekuchen".