Preheat the oven to 350°F. Lightly spray a pie pan with nonstick spray. Press one pie crust into the bottom of the pie pan. Line the crust with parchment paper and place dry beans or pie weights on top. Pre bake the crust for 15 minutes. Once baked, remove the parchment and beans or pie weights and place onto a cooling rack.
2 (9-inch) refrigerated pie crusts
To make the filling, whisk the sugar and flour together. In a separate, large bowl, whisk together the remaining ingredients, except the top pie crust layer. Whisk the sugar/flour mixture into the wet mixture. Pour the filling into the pre baked pie crust.
1½ cups granulated sugar, 2½ tablespoons all-purpose flour, 3 large eggs, 2 large egg yolks, 1 cup buttermilk, 10 tablespoons unsalted butter, 1 teaspoon pure vanilla extract, ½ teaspoon kosher salt
Unroll and lay the top crust over the surface of the filling. Press the edges together using your fingers or a fork. Use a sharp knife to cut slits in the center of the pie crust to allow steam to escape without breaking the crust.
Place the pie into the oven to bake for 45 minutes.
Once the pie has baked, the center will still feel a bit jiggly. Remove the pie from the oven and place onto a cooling rack to cool completely.
Once cooled, cover with tin foil and place in the fridge to chill for 4 hours before slicing and serving.