Combine 1 cup flour and 1/2 teaspoon salt; cut in 1/3 cup plus 1 tablespoon shortening with a pastry blender until the mixture resembles coarse meal. Sprinkle 2 tablespoons cold water (1 tablespoon at a time) over the surface; stir with a fork until dry ingredients are moistened. Shape into a ball. Chill.
Roll the pastry to 1/8 inch thickness on a lightly floured surface. Place in a 9 inch pie plate; trim off the excess pastry along the edges. Fold the edges under and flute; set aside.
Combine the unsweetened chocolate and 1/2 cup water in a small saucepan. Cook over low heat, stirring until chocolate melts. Add 2/3 cup sugar; stir well. Bring to a boil, stirring constantly. Remove from heat; add butter and 1 1/2 teaspoons vanilla, stirring until butter melts. Set aside.
Cream 1/4 cup shortening. Combine 1 cup flour, 3/4 cup sugar, baking powder, and 1/2 teaspoon salt. Add the flour mixture to the creamed shortening alternately with the milk, beginning and ending with the flour mixture. Mix just until blended after each addition. Add the egg; beat well. Stir in 1/2 teaspoon vanilla.
Pour the filling into the pastry shell. Drizzle the reserved chocolate mixture over the filling. Sprinkle with the pecans. Bake at 350 degrees for 45 to 50 minutes or until a wooden pick inserted in the center comes out clean. Garnish, if desired. Serve warm or cool.