Combine flour, cornmeal, and salt in a medium bowl; set aside. Beat granulated sugar and butter at medium speed with an electric mixer 2 minutes or until light and fluffy. Gradually add oil, beating just until blended. Add rosemary, orange zest, and vanilla. Beat in eggs, 1 at a time, until blended. Gradually beat in flour mixture at low speed just until blended. Pour batter into prepared pan.