In medium bowl, combine flour, orange zest, baking powder and salt. In large bowl, beat butter with electric mixer until light and fluffy. Add sugar 1/4 cup at a time, scraping down sides of bowl as needed; when combined, beat on medium speed for 2 minutes. Add eggs one at a time, beating well after each addition; add vanilla and orange extracts. Add half of flour mixture; beat on low speed until nearly combined. Add buttermilk to moisten; add in remaining flour mixture, beating until just incorporated. Spread batter evenly in pan.