Preheat oven to 325°

Crush Graham crackers, add butter and sugar; press onto base of 9 inch spring form pan. Chill

For the filling, place cream cheese in a large bowl. Beat with an electric mixer set on medium high speed for 2 minutes. Blend in the sugar. Add the flour and beat until well combined. On low speed, beat in the eggs, one at a time, just until blended, scraping the side of the bowl often. Add the sour cream, vanilla and beat until just blended.

Pour the filling over the pie crust.

Bake the cheesecake for 1 hour 15 minutes. Turn off oven and keep the oven door ajar. Let the cheesecake sit in oven for 1 hour. Transfer to a wire rack to cool completely. Run a knife around sides. Cover, chill for 6 hours or overnight.

When ready to serve, remove the pan sides. Slide the cheesecake onto a serving plate.