I haven't tried it yet but I will.
From the Cast Iron Collector website.
Cast Iron Skillet Cornbread
2 C. cornmeal
½ C. flour, sifted
1 tsp. baking powder
1 tsp. salt
1 egg, lightly beaten
2 C. buttermilk (or milk)
2 Tbl. vegetable oil
Set oven to 450°F. Put oil in a #8 (10") cast iron skillet and place in oven until set temperature reached. Mix together dry ingredients, and set aside. Whisk together egg and buttermilk, and mix with dry ingredients, adding wet to dry, until just combined. Carefully remove skillet from oven, pour hot oil into batter, and stir to mix. Pour batter into skillet, return to oven and bake for 20 minutes. Cornbread should be browned on top, and pulling away from sides of skillet. A toothpick stuck in the center should come out clean. Remove and allow to cool a few minutes before turning out onto a plate for slicing. Serve with butter or honey.
This is a basic cast iron cornbread recipe. There are several others with variations of ingredients, but all should include oiling and preheating of the cast iron pan, and most the step of adding hot oil to batter right before baking