Preheat oven to 400-degrees.
In large bowl, prepare the cornbread mix according to the package directions. Set aside.
In a large stockpot or Dutch oven over medium-high heat, brown the ground beef until no longer pink.
Reduce the heat to medium and add the chopped onion, red peppers, fire-roasted chiles, canned corn, tomatoes (with their juice), cumin, chili powder, salt, and pepper.
Bring the mixture to a simmer, and cook, stirring occasionally for 3-5 minutes.
Stir in the pasta and beef stock.
Cook, stirring occasionally for 5-7 minutes.
Spray a 13 x 9 baking dish with cooking spray.
Carefully spoon the chili mac into the prepared baking dish and top evenly with the shredded cheese.
Spoon the waiting cornbread mixture evenly over the chili mac and cheese.
Bake in a preheated 400-degree oven for 30 minutes, or until the cornbread crust is golden and when a toothpick inserted in the center of the crust comes out clean.
Cool for 10 minutes before serving.
Garnish with chopped scallions if desired.