Preheat oven to 325 degrees. With foil, line the bottom and sides of a 9" square baking pan, allowing foil to overhang slightly. Butter foil; set aside. On a square of wax paper, combine flour, baking powder and salt. In a small saucepan, combine chocolate morsels, butter, sugar and ornage juice; cook and stir over very low heat until chocolate and butter are melted. Remove from heat. Stir in orange peel and vanilla. Using wire whisk, beat in eggs one at a time. Add reserved flour mixture, beating until smooth; stir in nuts, spread in prepared pan. Bake until a wooden pick inserted in the center comes out clean, 23-25 minutes. Cool completely on a wire raack. Spread with ORANGE CREAM. Using a knife, mark CHOCOLATE ICING in 36 (1 1/2") squares. Refrigerate until Icing is firm,(about 25 minutes or place in freezer for 5 minutes.) Lift foil edges to remove from pan. Cut in squares. Refrigerate up[ to 4 days or wrap and freeze up to 1 month. ORANGE CREAM: In electric mixer, beat butter until creamy. Gradually add sugar, beating until fluffy.Beat in orange peel,milk, and vanilla. Makes 1 1/2 cups. CHOCOLATE ICING: In small saucepan combine chocolate morsels, butter and vegtable shortning. Stir over low heat until melted. Makes 1 cup.