Lemon Meringue Pie

Whisk the sugar, cornstarch, salt and water in a large (nonreactive) saucepan. Heat over medium heat until thickened and simmering, stirring often. Once it starts to simmer and turns translucent, whisk in the egg yolks one at a time, then the zest, lemon juice, and butter. Bring to a simmer, whisking constantly, then remove from heat.

Place a sheet of plastic wrap directly on the surface of the filling to keep it hot and prevent a skin from forming.

In a small saucepan, whisk cornstarch and water until combined. Bring to a simmer over medium-low heat, whisking occasionally at first and more frequently as it thickens. Once it simmers and turns translucent, remove from heat and set aside.

Adjust oven rack to the middle position and preheat to 325°F.

In a small bowl, whisk cream of tartar and sugar together. In a large mixer bowl, beat egg whites and vanilla for 1-2 minutes on medium-high until frothy. Beat in sugar mixture, 1 tablespoon at a time, until fully incorporated. Beat on medium speed until soft peaks form. Add cornstarch mixture, 1 tablespoon at a time, while still beating. Continue until stiff peaks form, about 1-2 minutes.

About a minute before the meringue is ready, reheat the lemon filling for at least 1 minute. Pour filling into prebaked pie shell, smoothing the top with a spatula.

Spoon small amounts of meringue around the edge of the filling, then the center, ensuring it attaches to the crust to prevent shrinking. Use a spoon to create decorative peaks on the meringue.

Bake the pie until the meringue lightly browns, about 20 minutes. Transfer to a wire rack and cool to room temperature. Serve the same day.