Preheat your oven to 325°F (160°C). In a mixing bowl, combine graham cracker crumbs, melted butter, and granulated sugar until well mixed. Press this mixture firmly into the bottom of a 9-inch springform pan, ensuring it's evenly spread. Bake for about 10 minutes until the crust is golden brown. Allow it to cool completely.

In another bowl, beat the cream cheese and sugar together on medium speed until smooth and creamy. Add eggs one at a time, mixing well after each addition. Blend in sour cream, lemon juice, lemon zest, and vanilla extract until fully combined. Pour this mixture over the cooled crust.

Place the springform pan in a larger baking pan filled with hot water. Bake in your preheated oven for 50-60 minutes, until the edges are set and the center is slightly jiggly. Let the cheesecake cool in the oven for 1 hour before refrigerating for at least 4 hours.

In a saucepan over low heat, whisk together egg yolks, sugar, lemon juice, and lemon zest for about 8-10 minutes until thickened. Stir in butter until melted and smooth, then pour over the cheesecake layer.

Beat the egg whites with cream of tartar on high speed until soft peaks form. Gradually add sugar, continuing to beat until stiff peaks form. Fold in vanilla extract.

Preheat the oven to 350°F (175°C). Spread the meringue over the lemon curd, creating decorative peaks. Bake for 10-15 minutes until golden brown. Let cool at room temperature before refrigerating for at least 1 hour before serving.