Preheat oven to 325°F
Wrap your springform pan in one layer of plastic wrap and then aluminum wrap so that both come up to the top of the springform pan, being careful not to poke a hole in either. You can roll the foil and plastic wrap at the top to keep it in place.
Place springform pan into another pan that is deep enough to hold the springform pan along with enough water so that the water comes up ½ to ⅔ of the way up the side of the springform pan. Don't add water yet.
Mix your nilla wafer crumbs and enough butter so that when squeezed, it sticks together. Press firmly into bottom of 9 inch spring form pan, using a drinking glass to make sure you get all the way around the edges.
Beat your softened cream cheese and sour cream together at medium speed until completely mixed, but careful not to overmix. Add sugar, flour and vanilla and mix until completely combined, making sure to stop and scrape down the sides and bottom of mixer bowl as needed. The mixture shouldn't have any lumps or unmixed cream cheese.
Add eggs one at a time, with mixer at lowest speed setting just until blended. You never want to mix at high speed or for too long because it will introduce too much air into the mixture and your cheesecake will sink and crack when you take it out of the oven. I will actually just mix with mixer for a little, then once all eggs have been added, I take and manually fold the mixture with a rubber scraper to make sure it's blended but not over mixed.
Fold cheesecake mixture into the springform pan, and level off the top with an offset spatula.
Bake for 1 hour and 5 minutes to 1 hour and 10 minutes until the center is almost set but still a bit jiggly. The cheesecake will continue to bake as it cools, so don't over bake.
Turn oven off, and carefully remove pan with water bath and cheesecake from the oven, and then quickly remove the cheesecake from the water bath pan and carefully remove the foil and plastic wrap and return the cheesecake by itself to the oven. leaving the oven off, slightly prop the oven door open and allow cheesecake to come down to room temperature slowly in the oven - this last part is the key to keeping your cheesecake from cracking on top.
Once cheesecake as reached room temperature you can remove from oven, and using an offset spatula carefully run it around the inside of the pan to loosen the cake from the sides. Refrigerate the cheesecake in the pan until completely set and cold.
Once the cheesecake is cold and set up, you can remove it from the springform pan, and put it onto a serving plate, or cake drum.
Slice into 14-16 pie sized serving pieces - depending upon how big you want the pieces.