Preheat oven to 350°F. Place a pan of water on the bottom oven rack to create steam. Line a 9-inch springform pan with parchment paper.

Make the Crust: In a bowl, combine graham cracker crumbs, sugar, and melted butter. Press into the bottom of the pan. Bake for 8–10 minutes. Let cool.

Prepare Cheesecake Filling: In a large bowl, beat cream cheese and sugar until smooth. Add sour cream, lemon juice, lemon zest, and flour. Mix to combine.

Add eggs one at a time, mixing just until combined (do not overmix).

Bake: Pour filling over the crust. Bake for 50–60 minutes, or until the edges are set and the center is slightly jiggly.

Cool: Turn off the oven and let cheesecake sit with the door cracked for 10–15 minutes. Remove and cool on a wire rack. Chill in the refrigerator for at least 6 hours or overnight.

Lemon Curd Layer: Once chilled, spread lemon curd evenly on top of the cheesecake. Chill for another hour.

Make Meringue: In a heatproof bowl over a double boiler, whisk egg whites, sugar, and cream of tartar until sugar dissolves and mixture is warm. Remove from heat and beat with a mixer until stiff peaks form. Add vanilla.

Finish: Spread meringue over the cheesecake, using a spoon to create peaks. Lightly toast using a kitchen torch or under the broiler until golden brown.

Refrigerate until ready to serve.