Preheat the oven to 325°F (163°C).

In a mixing bowl, combine the graham cracker crumbs, ½ cup of granulated sugar, and ½ cup of melted unsalted butter. Mix until well combined.

Press the mixture into the bottom of a 9-inch springform pan.

Bake the crust for 10 minutes until golden brown, then cool.

In a large mixing bowl, beat the softened cream cheese until smooth. Gradually incorporate 1 cup of granulated sugar.

Add ¼ cup of sour cream and eggs one at a time, mixing well after each.

Stir in vanilla extract, lemon zest, and fresh lemon juice until combined.

In a separate bowl, whip together the heavy cream, cornstarch, and salt to soft peaks, then fold into the filling.

Pour the filling into the cooled crust and smooth the top. Bake for 55-60 minutes until the edges are set.

Cool in the oven for an hour, then let sit at room temperature for 1 hour before refrigerating for at least 4 hours.

Beat the egg whites and cream of tartar until soft peaks form, then gradually add ¼ cup of sugar until stiff peaks form.

Warm the remaining lemon juice and drizzle into meringue while beating. Spread meringue over the cheesecake.

Increase the oven to 350°F (177°C) and bake the meringue for 8-10 minutes until golden.

Cool completely before refrigerating for 1 hour before serving.