Contrary to the name cheesecakes are prepared from cottage cheese. Cheesecakes have appeared in Russia a long time ago, and they are called cheesecakes, but not tvorozhnik because the word "cottage cheese" then didn't exist yet.
Russian cheesecake | Ecency
Ptitim with Tofu and Cod Cheeks\Ptitim mit Tofu und Kabeljau-Bäckchensvinsent ·