In a medium mixing bowl, mix together cornmeal, sweet rice flour, oat flour, and salt. Set aside.
Melt the butter in a medium skillet.
Combine the melted butter, sugar, and vegetable oil in the bowl of an electric mixer on low speed.
Add eggs and beat on medium-low until combined.
Combine buttermilk and baking soda in a cup and pour the mixture into the bowl, mixing on medium-low speed until combined.
Add the dry ingredients to the wet ingredients and mix on medium speed until just combined.
Add the corn and stir until scattered throughout.
Pour batter into the same skillet you used to melt the butter.
Bake for about 30-35 minutes, or until a toothpick inserted in the center comes out clean, or with just a few crumbs and the top is lightly browned.
Notes
If you don't have buttermilk - which happens often in my house - you can substitute with scant 1 cup milk mixed with 1 tablespoon white vinegar. The cornbread will still turn out just as flavorful!
This nutritional information has been automatically calculated, and as such, may be incomplete or inaccurate. Please reference the specific ingredients you use for the most accurate nutritional information.