Lightly grease the bottom and sides of a 9-inch springform pan.
Mix graham cracker crumbs and melted butter in a bowl until evenly moistened. Press crumb mixture into the bottom and about 1/2-inch up the sides of the springform pan.
Whisk flour, sour cream, and vanilla extract in bowl. Set aside.
Stir cream cheese and sugar with a wooden spoon in a large bowl until evenly incorporated, 3 to 5 minutes.
Pour milk into cream cheese mixture and whisk until just combined.
Whisk in eggs, one at a time, stirring well after each addition.
Pour mixture into prepared springform pan.
Bake in the preheated oven until the edges have nicely puffed and the surface of the cheesecake is firm except for a small spot in the center that will jiggle when the pan is gently shaken, about 1 hour.
When the cheesecake is done, turn off the oven and let it cool in the oven for 3 to 4 hours. This prevents any cracks from forming on the top of the cheesecake.
the original recipe called for 1 teaspoon each of lemon zest and orange zest. I prefer to not add them in.