Combine yeast and warm water (100° to 110°) in a 1-cup glass measuring cup; let stand 5 minutes.
Whisk together flour and next 5 ingredients in a large bowl. Cut 1 stick of butter into small pieces. Cut into flour mixture with a pastry blender until mixture resembles coarse meal. Add yeast mixture, buttermilk, and herbs; stir with a fork just until dry ingredients are moistened. Cover and chill dough for 1 hour.
Turn out dough onto a floured surface; knead lightly 5 times. Roll dough to 1/2" thickness; cut with a 2 1/2" round biscuit cutter. Place biscuits on 2 large baking sheets coated with cooking spray. Melt remaining 1 Tbsp. butter; brush lightly over biscuits.
Bake at 450° for 12 to 15 minutes or until golden.