Preheat the oven to 325°.
On a lightly floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim to 1/2 in. beyond the rim of the plate; flute edge. Place the pie plate on a rimmed baking sheet.
In a large bowl, beat sugar, eggs, buttermilk, melted butter, flour, vanilla and salt until blended. Pour into the crust.
Bake for around 50-60 minutes until top is light golden brown and center is almost set.
Cool on a wire rack.
Serve or refrigerate within 2 hours.
Note: Do not over-bake this pie to keep the surface from cracking. The center of the pie will still be slightly wobbly after baking but will set up as it cools.