(Hakhel) HaRav Binyomin Forst, Shlita, in The Halachos of Brachos (Artscroll) writes that the bracha on cheesecake with a crust added for flavor “as is generally the case” is a Borei Minei Mezonos. However, if the crust is added solely to hold the cheese, then the bracha on the cheesecake is Shehakol.
HaRav Yisroel Pinchos Bodner, Shlita in The Laws of Brochos (Feldheim) writes that if the cheesecake is made with a thin layer of dough which is being used merely to enhance the appearance of the cake, then the bracha is Shehakol. 
However, if the dough is being used for substance or flavor, the bracha is Borei Minei Mezonos. The after-bracha on cheesecake will usually be Borei Nefashos and not Al HaMichya, as one can eat a kezayis combination of cheese and flour within a kedai achilas peras of three minutes, but it is unlikely that one will consume a kezayis of Mezonos within the three minute span. In sum, on cheesecake, one bracha rishona is recited, which may likely be a Shehakol, but even if a Borei Minei Mezonos is recited, the bracha achrona will in ordinary circumstances be a Borei Nefashos! If you are in doubt as to the appropriate brachos on the cheesecake you will be consuming—why not bring two to your Rav—one for the Shaila—and one to him for Shavuos!
Note: A reader (Hakhel) wrote that if the cheesecake crust is made not from mezonos but from corn flakes, the bracha would still be Shehakol, as the corn flakes would be considered tofel to the ikar, which is the cheese cake. This appears correct, but if one has this issue, he should consult with his Rav to confirm—especially if the corn flakes are there because he especially enjoys their taste.
Leah says
Cheesecake filling is usually made with flour as well, not only the crust.
milchigs lover says
I guess it depends on the recipe; my cheesecake doesn’t have flour in the filling. Just cream cheese, sour cream, sugar, eggs, and vanilla.
mhj says
The article assumes that you know the intention of the baker as to whether the crust is added for flavor, to enhance the appearance or to the hold the cheese. This doesn’t help if you are a guest in someone’s home or purchased that cheesecake in a bakery.
milchigs lover says
In my opinion, American cheesecakes have crust for flavor. I’ve tasted cheesecakes in other countries where the crust was bland and blah, maybe those crusts would qualify as just being to hold the cheese.