Roll out your pie crust dough on a floured surface to about 1/8 inch thick. Carefully fit the rolled crust into a 9-inch pie plate, ensuring it adheres to the sides. Trim any excess dough hanging over the edges and crimp for a decorative touch. Once done, set the pie crust in the refrigerator to chill while you prepare the filling.

In a large mixing bowl, combine sliced fresh strawberries and rhubarb with sugar, cornstarch, sour cream, and vanilla extract. Gently fold the ingredients together until the fruit is well-coated and the mixture is evenly combined.

Preheat your oven to 375°F (190°C). Pour the filling into the chilled pie crust, spreading it evenly. Cover with a second layer of crust, sealing the edges by crimping them together. Cut several vents on top to allow steam to escape. Bake for 45-50 minutes until golden and bubbly.

After baking, remove the pie from the oven and let it cool on a wire rack for at least two hours. Once cooled, slice and serve, optionally with a dollop of whipped cream.