Combine first 4 ingredients in a large bowl.
Cut butter into flour mixture with a fork or pastry blender until crumbly; add buttermilk, stirring just until dry ingredients are moistened.
Turn dough out onto a lightly floured surface; knead 2 or 3 times.
Pat or roll to 1/2-inch thickness; cut with a 1 1/2-inch round cutter, and place on a baking sheet.
Bake at 400° for 15 minutes or until biscuits are golden.