01 - Preheat oven to 325°F. Line the bottom of a 9-inch springform pan with parchment paper and set aside.
02 - Combine graham cracker crumbs, melted butter, and sugar in a bowl until the mixture resembles wet sand. Press firmly and evenly into the bottom of the prepared pan. Bake for 10 minutes, then set aside to cool.
03 - In a large mixing bowl, beat the softened cream cheese with an electric mixer until completely smooth and free of lumps. Gradually add the 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, flour, and lemon juice. Mix until just combined, being careful not to overmix.
05 - Pour the filling over the cooled crust and smooth the top with a spatula. Bake at 325°F for 45 minutes, or until the edges are set but the center still has a slight wobble.
06 - Turn off the oven, crack the door open, and let the cheesecake remain inside for 1 hour. This gradual cooling prevents cracks from forming on the surface.
07 - Remove from the oven and allow to cool completely to room temperature. Refrigerate for at least 4 hours, preferably overnight, until fully set.
08 - Whisk together sour cream, powdered sugar, and vanilla extract until smooth. Spread evenly over the chilled cheesecake just before serving.