Preheat oven to 425° F. On a lightly floured surface, roll dough to fit a 9-inch pie plate. Crimp edge of crust. Line unpricked crust with a double thickness of foil. Fill with pie weights, dried beans or uncooked rice.
Place on a baking sheet; bake until edge is light golden brown, 15 minutes. Remove foil and weights; bake until bottom is golden brown, 5 minutes longer. Cool. Reduce oven setting to 325° F.
In a large bowl, beat butter and sugar until blended. Add eggs, 1 at a time, beating well after each addition. Beat in flour and salt. Gradually stir in buttermilk and vanilla.
Sprinkle pecans into crust and pour filling on top. Bake until center is set, 50-60 minutes. Cover top loosely with foil during the last 15 minutes if crust is browning too much.
Cool completely on a wire rack. Great served at warm temperature or warm with whipped cream. Refrigerate leftovers.