Instructions

1. Bake pie crust according to package or recipe instructions. Allow to cool.
2. Heat oven to 400 degrees. In a small bowl, beat egg yolks with fork. Set aside.
3. In a large saucepan, mix together sugar and cornstarch. Slowly stir in water and cook over medium heat, stirring constantly, until mixture thickens and boils. Boil and stir for 1 minute.
4. Immediately stir about half of the hot mixture into the egg yolks, then stir the combined yolks-sugar-cornstarch mixture back into the remaining hot mixture in the saucepan. Boil and stir for 2 minutes, then remove from heat. Stir in butter, lemon zest and lemon juice. Pour into cooled pie crust.
5. In a medium bowl, beat egg whites and cream of tartar on high speed until foamy. Beat in sugar, 1 tablespoon at a time, until stiff peaks form. Once your meringue is stiff and glossy, beat in vanilla.
6. Carefully spoon meringue onto hot pie filling, spreading all the way to the edge of the crust.