01 - Preheat the oven to 325°F. Grease a 9-inch springform pan and line the base with parchment paper.
02 - In a mixing bowl, combine graham cracker crumbs, melted butter, and sugar until evenly moistened. Press the mixture firmly into the bottom of the prepared pan to form an even layer. Bake for 10 minutes, then remove and let cool slightly.
03 - Using an electric mixer, beat the cream cheese on medium speed until completely smooth. Add sugar and continue beating until well combined. Add eggs one at a time, mixing thoroughly after each addition. Blend in sour cream, vanilla extract, flour, and salt until just incorporated — avoid overmixing to prevent cracking.
04 - Pour the filling over the cooled crust. Gently tap the pan on the counter to release any trapped air bubbles. Bake for 50 to 60 minutes until the edges are set but the center still has a slight jiggle.
05 - Turn off the oven, crack the door open, and let the cheesecake rest inside for 1 hour. This gradual cooling helps prevent surface cracks.
06 - Transfer the cheesecake to a wire rack to cool to room temperature, then refrigerate for at least 4 hours or preferably overnight for the best texture.
07 - If using the topping, whisk together sour cream, powdered sugar, and vanilla extract until smooth. Spread evenly over the chilled cheesecake before serving.
08 - For clean cuts, dip a sharp knife in hot water and wipe dry between each slice. Serve chilled.