Preheat oven to 425°.
Lightly spoon flour into dry measuring cups; level with a knife. Combine flour and the next 5 ingredients (flour through salt); cut in butter with a pastry blender or 2 knives until mixture resembles coarse meal. Add buttermilk; stir just until moist.
Turn dough out onto a lightly floured surface; knead lightly 4 times. Roll dough to a 3/4-inch thickness; cut with a 2 1/2-inch biscuit cutter. Place on a baking sheet. Lightly coat tops with cooking spray. Bake at 425° for 13 minutes or until golden.