Lemon Supreme Pie

1 9-inch pie crust, pre-baked
1 cup granulated sugar
1/4 cup cornstarch
1/4 teaspoon salt
1 1/2 cups water
3 egg yolks, beaten
2 tablespoons unsalted butter
1/4 cup fresh lemon juice
1 tablespoon lemon zest
1 cup heavy whipping cream
2 tablespoons powdered sugar
1 teaspoon vanilla extract

In a medium saucepan, combine the sugar, cornstarch, and salt. Gradually stir in the water until smooth.

Cook over medium heat, stirring constantly, until the mixture thickens and begins to boil. Boil for 1 minute, then remove from heat.

Stir a small amount of the hot mixture into the beaten egg yolks, then return the egg mixture to the saucepan, stirring constantly.

Bring the mixture back to a gentle boil and cook for 2 more minutes, stirring constantly.

Remove from heat and stir in the butter, lemon juice, and lemon zest until smooth.

Pour the lemon filling into the pre-baked pie crust. Let it cool to room temperature, then refrigerate for at least 2 hours until set.

In a medium bowl, whip the heavy cream with the powdered sugar and vanilla extract until soft peaks form.