Preheat the oven to 350 and grease a 9-inch round cast-iron skillet.  In a medium bowl, whisk together the oil, sour cream, eggs, onion and corn, and in a separate small bowl, whisk together the cornmeal, baking powder and salt.

Add the dry ingredients to the wet and use a sturdy spatula to stir until well combined.

Scrape half the batter into your prepared skillet, sprinkle the batter layer with about 3/4’s of the grated cheese, smooth on the remaining batter and top evenly with the remaining cheese.

Bake for 45 to 50 minutes until the top is golden brown and the center springs back to a light touch.  Allow the cornbread to sit and set in the skillet for about 20 minutes before slicing and serving.