01 - Preheat oven to 340°F. Line the bottom of a 9-inch springform pan with parchment paper.
02 - Pulse graham crackers until finely ground. Mix in melted butter, sugar, and salt. Press firmly into the bottom of the prepared pan. Bake for 10 minutes, then cool while preparing filling.
03 - Beat Greek yogurt, cream cheese, and sugar in a large bowl until smooth and creamy.
04 - Add eggs one at a time, mixing well after each addition. Stir in vanilla extract, lemon zest, lemon juice, cornstarch, and salt until fully incorporated.
05 - Pour filling over cooled crust. Smooth top with spatula. Bake for 50 minutes until center is just set but slightly wobbly.
06 - Turn off oven, crack door open, and let cheesecake cool inside for 1 hour. Remove from oven and cool to room temperature.
07 - Refrigerate for at least 4 hours, preferably overnight, until completely set.
08 - Mix sour cream or Greek yogurt with powdered sugar and vanilla. Spread over chilled cheesecake before serving.
09 - Dip a sharp knife in hot water between slices for clean edges. Serve chilled.