Combine okra and buttermilk in a large bowl; toss to coat. Combine cornmeal and next 3 ingredients in a medium bowl. Drain okra, discarding buttermilk. Toss okra in cornmeal mixture to coat. Pour oil to depth of 2 inches into a Dutch oven; heat to 350°. Fry okra, in batches, 4 minutes or until golden. Drain well on paper towels. Sprinkle with additional salt, if desired.