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