Sourdough Cornmeal muffins

12 muffins 

1 1/4 cup plain cornmeal
1 cup all-purpose flour

1/4 cup oatmeal

1/4 cup sourdough starter discard
1/4c tablespoon brown sugar 
1 tablespoon baking powder
1/2 tsp baking soda
1 teaspoon salt
2 eggs, lightly beaten

1/2 stick (1/4 cup)  butter, melted or 1/2 cup veg oil or melted shortening
1 (14.75 ounce) can creamed-style corn

Preheat oven to 400°F. Grease a 10" cast iron skillet or medium baking dish.