01 - Preheat the oven to 325°F (160°C). Grease a 9-inch springform pan and line the base with parchment paper.
02 - In a mixing bowl, combine the 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 crust. Bake for 10 minutes, then remove and let cool slightly.
03 - Using an electric mixer, beat the softened cream cheese on medium speed until completely smooth. Add the granulated sugar and beat until well combined. Add the eggs one at a time, mixing thoroughly after each addition. Blend in the sour cream, vanilla extract, flour, and salt until just incorporated — be careful not to overmix.
04 - Pour the filling over the cooled crust. Gently tap the pan on the counter a few times to release any trapped air bubbles.
05 - Bake for 50 to 60 minutes until the edges are set but the center still has a slight jiggle. Turn off the oven, crack the door open, and let the cheesecake rest inside the cooling oven for 1 hour.
06 - Remove the cheesecake from the oven and transfer to a wire rack to cool completely. Refrigerate for at least 4 hours, preferably overnight, for the best texture.
07 - In a small bowl, whisk together the sour cream, powdered sugar, and vanilla extract until smooth. Spread the topping evenly over the chilled cheesecake before serving.
08 - Use a hot, wet knife to slice the cheesecake for clean, even cuts. Wipe the blade between each slice.