Preheat oven to 350 degrees F (175 degrees C). Grease a 9-inch springform pan.
Mix graham cracker crumbs and melted butter in a bowl. Press onto the bottom of the prepared springform pan.
Combine Neufchatel cheese and sugar in a large bowl until smooth. Blend in milk, then mix in eggs one at a time, mixing just enough to incorporate. Mix in sour cream, vanilla extract, and flour until smooth. Pour cream cheese mixture into prepared crust.
Bake in preheated oven until center sets, about 1 hour. Turn oven off and let cake cook in oven with the door closed for 5 to 6 hours; this prevents cracking. Chill in refrigerator until ready to serve.
