Preheat the oven to 400ºF. Coat a 9x13 baking pan with cooking spray.
In a large bowl, whisk together flour, cornmeal, sugar, baking powder, and salt.
Add the milk, vegetable oil, and eggs, and fold to combine, being sure not to overmix. There should still be a few small lumps.
Pour the batter into the prepared pan, smooth out the top, and bake 25-30 minutes or until the edges are beginning to brown and a toothpick inserted in the center comes out clean.
Allow the cornbread to cool completely, preferably overnight.
Toast the cornbread
Preheat the oven to 300ºF.
Using your hands, break the cornbread up into bite size pieces and arrange them in a single layer on a half sheet baking pan. If you don’t have a half sheet, you can use two smaller pans, just be sure to crumble about ¾ of the cornbread.
Bake for 20 minutes, stirring once, or until toasted.
After removing from the oven, allow to cool enough to handle and transfer to a large bowl.
Prepare the stuffing
Preheat the oven to 375ºF. Coat a 9x13 baking pan with cooking spray and set aside.
Heat butter in a large skillet over medium heat.
Add the onion and celery and season with salt and pepper. Cook until slightly softened, 5-7 minutes.
Add the garlic, sage, and thyme, and cook, stirring, for 1 minute.
Add the vegetable stock and remove from the heat.
Pour the vegetable stock mixture into the bowl with the cornbread and add the pecans. Stir to combine.
Transfer the stuffing mixture to the prepared pan and spread out evenly. Bake 30-40 minutes or until the edges are crispy and everything is hot.
Tips for customizing
Make gluten-free cornbread stuffing by using a gluten-free cornbread recipe.
Make vegan cornbread stuffing by using a vegan cornbread recipe and substituting vegan butter for the butter in this recipe.
Swap the celery for leeks
Swap the pecans for walnuts, or omit entirely if you can’t enjoy nuts
Flavor your cornbread with cheese, jalapeños, or other seasonings for an easy twist
For extra decadence, drizzle the stuffing with 2 tablespoons melted butter after baking