01 - Preheat the oven to 325°F. Line the bottom of a 9-inch springform pan with parchment paper, ensuring it lies flat.
02 - Combine the graham cracker crumbs, melted butter, and sugar in a mixing 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 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, mixing thoroughly after each addition. Blend in the sour cream, vanilla extract, flour, and lemon juice. Mix until just combined—avoid overmixing to prevent air bubbles.
05 - Pour the filling over the cooled crust and smooth the surface with a spatula. Bake for 45 minutes, or until the edges are set but the center still has a slight wobble. Turn off the oven, crack the door open, and let the cheesecake rest inside for 1 hour.
06 - Remove the cheesecake from the oven and allow it to cool completely to room temperature. Refrigerate for at least 4 hours, preferably overnight, before serving.
07 - Whisk together the sour cream, powdered sugar, and vanilla extract until smooth. Spread evenly over the chilled cheesecake just before serving.