Preheat the oven to 325°F (160°C). Lightly grease a 9-inch springform pan and, if desired, line the base with parchment paper for easier release.
In a mixing bowl, combine the crushed graham crackers with the sugar. Pour in the melted butter and stir until the mixture takes on a damp, sandy consistency.
Press half of the prepared crust mixture firmly into the base of the springform pan. Bake for 10 minutes. Remove from the oven and allow it to cool briefly.
In a separate large bowl, beat together the softened cream cheese and sugar until smooth and light.
Add the eggs individually, ensuring each is fully incorporated before adding the next.
Blend in the vanilla, sour cream, flour, lemon juice if using, and a pinch of salt. Mix until the filling is completely smooth and uniform.
Carefully pour the cheesecake batter over the cooled crust base.
Evenly distribute the remaining crumb mixture over the top of the cheesecake filling. Lightly press it into place without compressing it into the batter.
Bake for 50 to 60 minutes, or until the outer edges are set and the center has a slight wobble.
Turn off the oven, open the oven door slightly, and let the cheesecake rest inside for 1 hour to cool gradually.
Remove the pan from the oven and allow the cheesecake to cool completely at room temperature.
Transfer to the refrigerator and chill for a minimum of 4 hours or overnight prior to slicing and serving.