Preheat your oven to 300°F (150°C).

Begin by creaming the sugar and butter together until well blended.

Add the eggs one at a time, beating well after each addition, until the mixture is smooth.

Stir in the vanilla extract, salt, and flour.

Next, blend in the buttermilk.

Prepare a baking sheet by lining it with aluminum foil. This will catch any overflow. Place the pie shell on the prepared baking sheet.

Fill the pie shell with the buttermilk mixture, making sure to fill it up to the top. Pour any excess mixture into an ungreased custard cup.

Bake in the preheated oven for approximately 1 hour and 10 minutes.

Once done, remove the pie from the oven and let it set until it is almost cool before serving.

Store the pie covered in the refrigerator.

Enjoy your delicious buttermilk pie!