Savannah High Apple Pie

6 cups all-purpose flour, plus 3/4 cup for filling and 1 cup for streusel 2 cups butter-flavored solid shortening 1 tablespoon salt 3/4 cup cold water 24 apples, preferably Golden Delicious or Granny Smith, peeled, quartered and thinly sliced 1 1/2 cups sugar, plus 4 tablespoons to sprinkle on top crust 1 tablespoon ground cinnamon, plus 1 teaspoon for streusel 1/2 cup butter, softened, plus 4 tablespoons to top pie filling 1 cup brown sugar, firmly packed 1/2 cup pecans, divided 1/4 cup milk 2 cups (12 oz) melted caramel 3 tablespoons evaporated milk 1 1/2 cups pecan pieces, chopped