Preheat oven to 425°. In a large bowl, whisk the first 6 ingredients. Cut in butter until mixture resembles coarse crumbs. Add buttermilk; stir just until moistened. Turn onto a lightly floured surface; knead gently 8-10 times., Pat or roll dough to 3/4-in. thickness; cut with a floured 2-1/2-in. biscuit cutter. Place 2 in. apart on a greased baking sheet. Bake 10-12 minutes or until golden brown. Serve warm.