Weigh or lightly spoon flour into dry measuring cups, and level with a knife. Combine flour and next 3 ingredients (through salt); stir with a whisk. Place sugar, butter, and vanilla in a large bowl; beat with a mixer at medium speed until light and fluffy. Add eggs, 1 at a time, beating well after each addition. Add flour mixture and buttermilk to sugar mixture, beginning and ending with flour mixture.
Spoon batter into 2 (8" x 4") loaf pans coated with cooking spray. Bake at 350° for 50 - 60 minutes or until a wooden pick inserted in the center comes out clean. Cool in pans 10 minutes on a wire rack. Remove from pans. Cool completely on a wire rack.