Preheat the oven to 400°F / 205°C. Mix 1½ cups of all-purpose flour, ⅓ cup of sugar, half of ½ teaspoon of salt, 8 tablespoons of softened butter, and 1 large egg into a dough.
Press the dough into a 10in / 25cm springform pan. Bake for about 15 minutes, until lightly browned, then reduce the oven to 325°F / 165°C.
On low speed, beat 900g of cream cheese, at room temperature, with 1¾ cups of sugar and 3 tablespoons of all-purpose flour until smooth. Beat in the grated zest of 1 lemon, the remaining salt, and 1 teaspoon of vanilla extract.
Still on low speed, beat in 5 large eggs, one at a time, then ½ cup of sour cream. Pour over the crust.
Bake for 45-50 minutes, until the filling 1in / 2.5cm from the edge reaches 175°F / 79°C. Turn off the oven, prop the door open and leave the cheesecake inside for 1 hour.
