Preheat the oven to 325°F (165°C). In a medium bowl, combine the graham cracker crumbs, melted butter, and 2 tablespoons of sugar. Press the mixture firmly into the bottom of a springform pan, then bake for 8-10 minutes until golden. Allow to cool.

In a large mixing bowl, beat the cream cheese and 1 cup of sugar until smooth and creamy. Add the eggs one at a time, beating well after each addition. Stir in 1/4 cup of lemon juice, lemon zest, and sour cream, mixing until fully combined. Pour this creamy mixture into the cooled crust, smoothing the top with a spatula.

Bake the cheesecake at 325°F (165°C) for 45-50 minutes. It should be slightly wobbly in the center. Turn off the oven and leave the cheesecake inside for 1 hour with the door ajar. Once finished, refrigerate for at least 4 hours or overnight to set.

To prepare the lemon curd, whisk together 1/2 cup of lemon juice, 1/2 cup of sugar, and 2 eggs in a saucepan over medium heat. Stir constantly until the mixture thickens, which should take about 8-10 minutes. Once thick, stir in the cubed butter and lemon zest until smooth. Let it cool to room temperature before spreading it over the chilled cheesecake.

For the meringue, beat the egg whites and cream of tartar until soft peaks form. Gradually add in 1/4 cup of sugar, continuing to beat until stiff peaks form. Spread the meringue over the lemon curd, ensuring to seal the edges well against the crust to prevent burning.

Bake the meringue at 350°F (175°C) for 8-10 minutes or until golden brown. Once done, let the cheesecake cool completely before serving.