1. Preheat oven to 350. Grease 9in springform pan.
2. In a medium bowl, mix graham cracker crumbs with melted butter. Press onto bottom of springform pan.
3. In a large bowl, mix cream cheese with sugar until smooth. Blend in milk, then mix in the eggs, one at a time, mixing just enough to incorporate. Mix in sour cream, vanilla extract, and flour until smooth. Pour filling into prepared crust.
4. Bake in preheated oven for 1 hour. Turn the oven off, and let cool in the oven with the door closed for 5-6 hours; this prevents cracking. Chill in refrigerator until serving.