1. Preheat oven to 325°F (160°C). Mix graham cracker crumbs and sugar in a bowl. Stir in melted butter until evenly moistened. Press mixture into a 9-inch springform pan. Bake for 10 minutes, then cool.

2. In a large bowl, beat cream cheese until smooth. Add sugar, sour cream, flour, vanilla, lemon zest, and lemon juice. Mix until just combined. Beat in eggs one at a time on low speed.

3. Pour cheesecake batter over the crust. Tap the pan gently to release air bubbles. Bake for 50–60 minutes, or until the center is set with a slight jiggle. Turn off oven, crack door, and let cool inside for 1 hour. Chill in fridge for 6 hours or overnight.

4. In a heatproof bowl over simmering water, whisk together egg yolks, sugar, lemon juice, and zest for the lemon curd. Stir constantly until thickened, about 8–10 minutes. Remove from heat and stir in butter until smooth. Strain and let cool.

5. Spread cooled lemon curd over chilled cheesecake. Refrigerate while making meringue.

6. For the meringue, whisk egg whites, sugar, and cream of tartar in a heatproof bowl over simmering water until sugar dissolves and mixture reaches 160°F. Beat on high until stiff, glossy peaks form. Add vanilla.

7. Pipe meringue over cheesecake and use a kitchen torch to toast until golden. Serve immediately or refrigerate until ready to serve.