Ok, I'll start by being honest.
I have made this recipe a number of times before, but I discovered it after I started eating gluten-free. Every time I made it, my family/friends had this reaction: mouths full, crumbs falling out "oh-my-goodness-this-cornbread-is-SOOO-good!" crumbs, crumbs, mmms, smiles. I'd stand there wistfully, saying "thanks," wishing I could try a piece.
So, this version of the recipe is new to me. :)
I substituted the wheat flour with Bob's Gluten Free All Purpose Baking Flour. (Some people don't love Bob's AP mix because it includes a lot of bean flour, but I am not bothered by the beans' taste. In fact, I appreciate the additional protein/iron). When I have made it gluten-full, I've used King Arthur White Wheat flour.
I added an additional egg. I've read that adding an egg can be a good choice to help hold your baked goods together if you are trying to avoid xantham gum in your GF baking adventures, which I am. And I used Arrowhead Mills Organic Yellow Cornmeal. I'm new to baking in a GF manner, so I had no idea what I'd end up with.
What I ended up with was something my gluten-loving husband declared to be the best cornbread I'd ever made and the thing my 4-year-old woke up asking for for breakfast this morning. I have to admit, it was really, really good. I might try dropping the baking powder down to just 1 T. and substituting some of the sugar for honey/maple syrup/cane juice next time. But it was yummy. Sweet, moist, held together. I felt accomplished in my experiment and it boosted my GF baking confidence, even though I was using a pre-mixed flour. Baby steps and grace. And delicious corn bread.