Heat oven to 400 degrees F. Prepare cornbread mix per package directions.
Bake at 400 degrees F for 20 minutes or until toothpick inserted in center comes out clean.
Cool completely on wire rack.
Reduce oven heat to 350 degrees F. Coat a 2-quart baking dish with nonstick cooking spray.
Cut cornbread into 1/2-inch cubes (10 cups). Place in bowl with 1 can (11 oz) Mexicorn, drained, 6 thinly sliced scallions, 2 cups low-sodium chicken broth, 1 cup shredded pepper Jack cheese, 1 tbsp dried oregano and 3/4 tsp cumin; stir until blended.
Pour mixture into dish; bake at 350 degrees F for 50 minutes. Top with 1/4 cup shredded pepper Jack cheese; bake 10 minutes.