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 pan bottom. Bake for 10 minutes, then cool.
03 - Beat Greek yogurt, cream cheese, and sugar in large bowl until smooth and creamy.
04 - Add eggs one at a time, mixing well after each addition. Stir in vanilla, lemon zest, lemon juice, cornstarch, and salt until fully combined.
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 cool cheesecake inside for 1 hour. Remove and cool to room temperature.
07 - Refrigerate for at least 4 hours, preferably overnight, until completely chilled.
08 - Mix sour cream or Greek yogurt with powdered sugar and vanilla. Spread over chilled cheesecake before serving.
09 - Slice with sharp knife dipped in hot water for clean edges.