Preheat oven to 325°. In a bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Add eggs, 1 at a time, beating well after each addition. Blend in flour, lemon juice and vanilla. Stir in buttermilk and pecans., On a lightly floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. deep-dish pie plate. Trim crust to 1/2 in. beyond rim of plate; flute edge., Add filling. Bake until set, 55-60 minutes. Cool on a wire rack. Store in the refrigerator.