Preheat your oven to 375°F and grease a baking dish. Whisk together the cornmeal, flour, baking powder, baking soda, and salt in one bowl. In another, combine the melted butter, honey, egg, and buttermilk. Fold the wet mixture into the dry ingredients and pour it into the dish. Bake for about 20 to 25 minutes until golden and a toothpick comes out clean.
Once the cornbread has cooled, cut it into one-inch cubes and spread them on a baking sheet. I like to leave mine out overnight, or you can toast them in a low oven for about 15 minutes. Drying out the cornbread helps it soak up the broth without turning mushy later.
In a large skillet, melt the butter and sauté the chopped onion and celery until softened, about five minutes. If you're using sausage, brown it in the same pan, breaking it apart as it cooks. This step builds so much flavor into your stuffing base.
In a large bowl, whisk the broth together with the eggs until fully combined. This liquid mixture is what brings the whole stuffing together and keeps it moist as it bakes, so don't rush this step.
Add the cubed cornbread, cooked vegetables, sausage, herbs, chopped apple, and nuts into the broth mixture. Gently toss everything together until the cornbread is evenly coated but not falling apart into mush.
Spoon the mixture into a greased baking dish, cover with foil, and bake at 375°F for about 30 minutes. Remove the foil for the last 10 to 15 minutes so the top turns crisp and golden brown.
Let the stuffing sit for about five to ten minutes once it comes out of the oven. This helps it set slightly and makes serving so much easier without everything falling apart on the spoon.