01 - Preheat the oven to 325°F. Line the bottom of a 9-inch springform pan with parchment paper and set aside.
02 - Combine the graham cracker crumbs, melted butter, and granulated sugar in a mixing bowl. Stir until the mixture resembles wet sand. Press firmly and evenly into the bottom of the prepared springform pan. Bake for 10 minutes, then remove and let cool completely.
03 - In a large bowl, beat the softened cream cheese with an electric mixer until completely smooth and free of lumps. Gradually add the granulated sugar and continue mixing until well incorporated.
04 - Add the eggs one at a time, beating well after each addition. Blend in the sour cream, vanilla extract, all-purpose flour, and lemon juice. Mix until just combined—do not overmix to prevent air bubbles.
05 - Pour the filling over the cooled crust and smooth the surface with a spatula. Bake at 325°F for 45 minutes, or until the edges are set but the center still has a slight jiggle.
06 - Turn off the oven and crack the door open. Leave the cheesecake inside for 1 hour to cool gradually, which helps prevent cracking on the surface.
07 - Remove the cheesecake from the oven and allow it to reach room temperature. Transfer to the refrigerator and chill for at least 4 hours, preferably overnight, until fully set.
08 - Whisk together the sour cream, powdered sugar, and vanilla extract until smooth. Spread the topping evenly over the chilled cheesecake before slicing and serving.