Place buttermilk in a 2-cup glass measure; microwave at HIGH 1 minute or until buttermilk reaches 130°.
Combine baking mix and next 4 ingredients in a large bowl; cut in margarine with a pastry blender until mixture resembles coarse meal. Add buttermilk, stirring with a fork just until dry ingredients are moistened.
Sprinkle flour evenly over work surface. Turn dough out onto floured surface, and knead 4 or 5 times. Roll dough to 1/2-inch thickness; cut into rounds with a 2 1/2-inch biscuit cutter. Place rounds on a baking sheet coated with cooking spray. Coat rounds with cooking spray, and sprinkle with parsley. Cover and let rise in a warm place (85°), free from drafts, 10 minutes. Bake at 400° for 14 minutes or until biscuits are golden.