1. Preheat oven to 350°.
2. Weigh or lightly spoon flour into dry measuring cups; level with a knife. Combine flour, cornmeal, baking powder, and salt in a medium bowl, stirring with a whisk.
3. Place sugar and butter in a large bowl; beat with a mixer at medium speed until well blended (about 5 minutes). Add oil, syrup, rind, and egg whites, beating until blended. Gradually add flour mixture to sugar mixture; beat well. Drop dough by level tablespoonfuls 1 inch apart on 2 baking sheets coated with cooking spray. Bake at 350° for 10 minutes or until edges are golden. Place baking sheet on a wire rack; cool completely.