Preheat oven to 350°F (175°C) and grease a 9-inch springform pan.
Mix graham cracker crumbs, 2 tablespoons sugar, and melted butter for the crust. Press into the bottom of the pan and bake for 10 minutes. Set aside to cool.
In a large bowl, beat cream cheese, 1 cup sugar, and eggs until smooth. Add sour cream, lemon zest, lemon juice, and vanilla extract, and mix well. Pour the cheesecake filling into the cooled crust and bake for 50 minutes. Turn off the oven and let it cool in the oven with the door cracked for 1 hour. Chill for at least 2 hours.
For the lemon curd: In a medium saucepan, whisk together egg yolks, ½ cup sugar, ¼ cup lemon juice, and lemon zest. Cook over medium heat while stirring constantly until thickened (about 5-7 minutes). Remove from heat and stir in softened butter until fully incorporated. Let it cool, then layer over the chilled cheesecake.
For the meringue: Beat egg whites, cream of tartar, and 1 cup sugar until stiff peaks form. Spoon the meringue on top of the curd and lightly brown with a kitchen torch or under the oven’s broiler.
Chill completely before slicing and serving.