Preheat oven to 400°.
Combine first 4 ingredients in a large bowl; cut in shortening with a pastry blender or 2 knives until mixture resembles coarse meal. Stir in green onions. Add buttermilk, stirring just until flour mixture is moist.
Drop batter by heaping tablespoons onto a baking sheet coated with cooking spray. Bake at 400° for 15 minutes or until lightly browned.