Add the cubed or crumbled cornbread, lettuce (optional), diced tomatoes, beans, sweet corn kernels, diced bell pepper, red onion, bacon, and ½ cup of shredded cheddar cheese to a large mixing bowl; or layer the ingredients in a large baking dish.
In a separate small bowl, whisk together the mayonnaise, sour cream or Greek yogurt, lemon or lime juice, dried parsley, garlic powder, onion powder, dried dill, salt, and pepper to make the salad dressing.
Pour the dressing over the salad ingredients and gently toss or stir until all of the ingredients are evenly coated. Transfer the salad to a serving dish if the salad was mixed in a bowl.
Sprinkle the remaining cheese and diced green onions over the salad. If desired, garnish the cornbread salad with chopped fresh cilantro or parsley.
Serve the cornbread salad immediately, or refrigerate the salad for at least 1 hour before serving to allow the flavors to meld.