In a bowl, combine the first six ingredients; cut in margarine until the mixture resembles coarse crumbs. Combine eggs and cream; stir into dry ingredients just until moistened. Turn onto a floured surface; gently pat into a 7 inch circle, ¾ inch thick. Cut into eight wedges. Separate wedges; place on a lightly greased baking sheet. Brush tops with buttermilk. Let rest 15 minutes. Bake at 450 degrees for 14-16 minutes or until golden brown.