Remove pits and cut plums in quarters. Combine with sugar, flour, salt and cinnamon. Turn into pie shell and sprinkle with lemon juice. Add Spicy Topping.
Place pie in heavy brown paper bag from supermarket. Be sure bag is large enough to cover pie loosely. Fold over open end twice to close, and fasten with paper clips. Set on baking sheet in hot oven (425°F.); bake 1 hour. Remove from oven, let rest a few minutes before removing pie from paper bag. Partially cool on rack.