1In large bowl, beat granulated sugar, shortening and softened butter with electric mixer on medium speed, scraping bowl often, until creamy. On low speed, beat in vanilla and egg. Stir in flour blend, baking powder and salt until well mixed. Divide dough in half; shape each half into disk. Wrap in plastic wrap; refrigerate about 1 hour or until firm.
2Heat oven to 375°F. On work surface lightly sprinkled with flour blend, roll each half of dough to 1/4-inch thickness. Cut with 2 1/2-inch cookie cutter. Place 1 inch apart on ungreased cookie sheets.
3Bake 8 to 12 minutes or until edges are lightly browned. Let stand 2 minutes on cookie sheet; remove to cooling rack. Cool completely, about 15 minutes. Stir together Glaze ingredients. Spread on cookies. Sprinkle with additional granulated sugar, if desired.