In large bowl, beat shortening, 1/2 cup granulated sugar and the orange zest with spoon until blended. Beat in 1 egg. Stir in flour mixture until well blended. Knead 5 to 10 times or until dough is smooth. Shape dough into 6- by 5-inch rectangle; divide in half, and wrap each in plastic wrap. Refrigerate about 2 hours or until dough is firm and cold.