Preheat oven to 350 degrees. Sprinkle one pie shell with 2 teaspoons sugar and bake for about 10 minutes or until shell is light golden brown. Remove from oven and set aside. In a large Dutch oven or pot, combine apple slices, butter, brown sugar, flour, lemon juice, vanilla, mace or nutmeg, cinnamon, allspice and salt. Over medium high heat, cook apples until soft but not mushy, about 10 minutes. Pour apples into baked pie shell. Cover apples with second unbaked pie shell, crimping around the edges. Bake at 350 degrees for about 15 minutes or until top crust is golden brown. While pie is baking, make praline topping. In a medium saucepan, heat butter. Stir in brown sugar and cream. Slowly bring to a boil then remove from heat. Stir in pecans. Spread over top of pie and brush edges of pie with caramel mixture. Return to oven and cook for 5 minutes or until topping bubbles and top is richly glazed. Cool at least one hour before serving.