Prepare the Crust:

• Preheat your oven to 350°F (175°C).
• Roll out the pie crust into a 9-inch pie dish. Trim and crimp the edges.
• Prick the bottom with a fork and blind bake for 10-12 minutes until lightly golden. Remove and let cool.

Make the Lemon Filling:

• In a medium saucepan, whisk together sugar, cornstarch, and salt.
• Gradually stir in water, lemon juice, and lemon zest.
• Cook over medium heat, stirring constantly until the mixture thickens and comes to a boil.
• Reduce the heat to low. Whisk in the egg yolks one at a time, then add butter. Stir until smooth and combined.
• Remove from heat and pour the lemon filling into the cooled pie crust.

Prepare the Meringue:

• In a large mixing bowl, beat the egg whites on medium speed until frothy.
• Add the cream of tartar and continue to beat until soft peaks form.
• Gradually add sugar, 1 tablespoon at a time, beating on high until stiff, glossy peaks form. Beat in vanilla extract.

Assemble the Pie:

• Spread the meringue over the hot lemon filling, ensuring it touches the crust edges to prevent shrinking.
• Shape peaks with a spatula for decorative touch.

Bake the Pie:

• Bake in the preheated oven for 10-15 minutes, until the meringue is golden brown.
• Remove from the oven and let cool at room temperature for at least 1 hour, then refrigerate for 3-4 hours before serving.