Combine flour, baking powder, and sugar; stir well. Cut in shortening with a pastry blender until mixture resembles coarse meal. Sprinkle buttermilk evenly over flour mixture, stirring until dry ingredients are moistened.
Spoon dough into a lightly greased 6-cup ovenproof ring mold. Bake at 400° for 15 minutes or until lightly browned.