Step 1

Preheat oven to 350 degrees F (175 degrees C).

Step 2

Lightly grease the bottom and sides of a 9-inch springform pan.

Step 3

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.

Step 4

Whisk flour, sour cream, and vanilla extract in bowl. Set aside.

Step 5

Stir cream cheese and sugar with a wooden spoon in a large bowl until evenly incorporated, 3 to 5 minutes.

Step 6

Pour milk into cream cheese mixture and whisk until just combined.

Step 7

Whisk in eggs, one at a time, stirring well after each addition.

Step 8

Stir in lemon zest, orange zest, and sour cream mixture; whisk until just incorporated.

Step 9

Pour mixture into prepared springform pan.

Step 10

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.

Step 11

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.