Heat oil in a medium skillet over medium heat. Add bell pepper and next 3 ingredients; sauté 5 minutes. Set aside.
Combine flour and next 5 ingredients in a medium bowl; stir well. Add bell pepper mixture and corn; stir well. Make a well in center of mixture. Combine buttermilk and egg; stir well. Add to dry ingredients, stirring just until dry ingredients are moistened.
Heavily coat cast-iron cornstick pans with cooking spray, and place in a 400 degrees oven for 10 minutes. Spoon batter evenly into pans. Bake at 400 degrees for 20 minutes or until lightly browned. Remove cornsticks from pans immediately, and serve warm.