Preheat your oven to 425°F (220°C).
In a mixing bowl, combine the halved strawberries, granulated sugar, cornstarch, lemon juice, and vanilla extract. Gently stir to coat the strawberries and allow the flavors to meld for about 10 minutes.
Roll out the pre-made pie crust and place it in the 9-inch pie dish, pressing it gently into the sides. Trim any excess dough hanging over the edges.
Pour the strawberry mixture into the crust and spread it evenly. Dot the top with small pieces of butter.
Cover the pie with a second layer of pie crust or leave it open-faced. If using an upper crust, make slits in the top to allow steam to escape, and crimp the edges to seal.
Bake in the preheated oven for 30-35 minutes or until the crust is golden brown and the filling is bubbly.
Remove the pie from the oven and allow it to cool on a wire rack for at least 2 hours before slicing.
Serve each slice with a dollop of whipped cream if desired.