Prepare the pie crust: If using a homemade pie crust, roll it out and fit it into a 9-inch pie dish. If using a pre-made crust, simply place it in the pie dish. Bake the crust according to the package instructions (or until golden brown if homemade). Allow it to cool completely before filling.

1. Make the strawberry filling: In a medium saucepan, combine the sugar, cornstarch, water, and lemon juice. Bring the mixture to a boil over medium heat, stirring constantly. Once it starts to boil, reduce the heat and simmer for about 2 minutes, or until the mixture thickens.
2. Add the strawberries: Remove the saucepan from the heat and stir in the vanilla extract. Gently fold in 3 cups of the halved strawberries, ensuring they are evenly coated in the syrupy mixture. Allow the mixture to cool for a few minutes.
3. Assemble the pie: Pour the strawberry filling into the prepared pie crust, spreading it evenly. Arrange the remaining 1 cup of halved strawberries on top, adding a decorative touch.
4. Chill the pie: Refrigerate the pie for at least 4 hours, or until the filling has set and the pie is firm.
5. Serve: Before serving, top the pie with whipped cream (optional) and enjoy!