Preheat your oven to 400°F (200°C). In a large bowl, whisk together cornmeal, flour, baking powder, salt, and sugar. In a separate bowl, beat the egg with milk and vegetable oil. Combine wet and dry ingredients, stirring until just mixed. Pour into a greased 8-inch square baking pan and bake for 20-25 minutes until golden brown. Let cool completely, then crumble into bite-sized pieces.

In a medium bowl, whisk together mayonnaise, sour cream, and ranch seasoning mix until smooth and well combined. This creamy dressing will bind all the layers together and add that signature Southern flavor.

In a large trifle bowl or clear glass dish, start with a layer of crumbled cornbread. Top with a generous spread of the creamy dressing. Add layers of tomatoes, bell peppers, red onion, corn, black beans, and turkey ham. Repeat the layers until all ingredients are used, ending with a final drizzle of dressing.

Sprinkle shredded cheddar cheese and green onions over the top. Cover and refrigerate for at least 2 hours (or overnight) to allow flavors to meld. Garnish with fresh parsley before serving.