Prepare the Crust:
Preheat your oven to 350°F (175°C).
In a medium bowl, combine the graham cracker crumbs, granulated sugar, and melted butter. Mix until the crumbs are evenly coated.
Press the crumb mixture firmly into the bottom of a 9×13-inch baking dish.
Bake for 10 minutes, then set aside to cool.
Make the Lemon Filling:
In a medium saucepan, whisk together the granulated sugar, lemon juice, lemon zest, egg yolks, cornstarch, and water.
Cook over medium heat, stirring constantly, until the mixture thickens and comes to a boil.
Once thickened, remove from heat and pour the lemon filling over the cooled crust.
Prepare the Meringue:
In a large bowl, beat the egg whites with an electric mixer until foamy.
Add the cream of tartar and continue to beat until soft peaks form.
Gradually add the granulated sugar, one tablespoon at a time, beating until stiff peaks form and the sugar is dissolved.
Beat in the vanilla extract.
