Preheat the oven to 350°F and lightly grease a large baking sheet.
Add the cubed day-old cornbread to a large baking sheet. Drizzle with 1 tablespoon of oil and gently flip/toss. Drizzle with the remaining 1 tablespoon of oil and gently toss again.
Sprinkle salt over the cornbread, and gently toss.
Spread the cornbread cubes out so they are in one even layer. Bake for 15–20 minutes, gently flipping once halfway through, until the croutons are crisp and lightly golden. Let cool slightly.
In a bowl, whisk together the buttermilk, mayo, and ranch packet. Drizzle in BBQ sauce a little at a time until it reaches the flavor you like. Set aside.
Once the BBQ chicken has rested, chop it into small pieces and toss with BBQ sauce.
Assemble the salad with your chopped salad base, BBQ chicken, rinsed black beans, crispy bacon, cheese, and cornbread croutons.
Drizzle with BBQ ranch, toss if desired, and serve right away.