This New York style cheesecake is made with cream cheese, sour cream, eggs, and a subtle hint of lemon that does not dominate its flavor.
Break up half of the Graham crackers into pieces and place in a blender. Whirl at low speed for about 15 seconds. Place a colander over a large bowl and pour the blended Graham crackers into the colander. Repeat for the remaining crackers.
Use a large spoon or soup spoon to stir the Graham cracker crumbs in the colander so that they fall into the bowl below. Return the large pieces that remain to the blender and repeat the process. Please note: You can skip these first two steps by buying Graham cracker crumbs in a box. Check your local grocery store. They will cost more but save a little time.
Measure the Graham cracker crumbs to make sure that you have 1-3/4 cups. Add the 6 Tablespoons of butter to the Graham cracker crumbs in the bowl. Stir until well blended.
Coat the sides and bottom of a 9-inch springform pan with butter. Simply rub the pan with the end of a stick of butter until thoroughly coated. Add the Graham cracker mix and spread evenly along the sides and bottom of the pan. Use a large spoon to press the crumbs up against the side of the pan. Leave the bottom for last. Set aside until ready to use.
The cream cheese should be at room temperature. Place the three blocks of cream cheese in the bowl of an electric mixer. Beat at a low speed for about 1 minute until the cheese is creamy without any lumps.
Add 1-1/2 cups sugar, 3 Tablespoons fresh lemon juice, 1-1/2 teaspoons vanilla flavoring, and 1/4 teaspoon salt. Beat again until sugar has been mixed into batter.
Add the eggs, two at a time, and beat for about 30 seconds after each addition. Do not beat too long after adding the eggs. You do not want to beat a lot of air into the batter.
Pour the cheesecake filling into the prepared graham cracker crust. Bake in a preheated 325° oven for 65 minutes (1 hour and 5 minutes). Remove from oven and place on a wire rack to cool. Let cool for 25 to 30 minutes. The amount of time you wait before adding the sour cream topping is critical. If you do not wait for the recommended 25 minutes, then the weight of the topping will cause the center to collapse, causing the filling to have a concave appearance. If you wait more than 30 minutes, you increase the chances that the filling will crack. This is not a real issue because the topping will cover any cracks in the filling. However, if you wait too long, the crust around the top may begin to collapse and fall onto the filling.
In a large bowl combine the 3 cups sour cream, 6 Tablespoons sugar, and 1-1/2 teaspoons vanilla flavoring. Stir together until well blended.
Gently spoon the sour cream mixture over the top of the cheesecake filling.
Spread over the top to an even thickness. Bake in a preheated 325° oven for exactly 12 minutes. Allow to cool on a cooling rack for at least 30 minutes before placing in the refrigerator to cool.
Refrigerate the cheesecake for at least 6 hours. You want the cheesecake to be completely chilled before you cut into it. Remove the outer ring so that you can cut the cake into 12 equal size pieces.