In a large skillet, cook beef and sausage over medium heat until no longer pink; drain. Stir in the corn, water and brown gravy mix. Bring to a boil; cook and stir for 1 minute or until thickened. Spoon into a greased 8-in. square baking dish.
Prepare cornbread batter according to package directions; stir in the bacon bits, pepper and garlic powder. Spread over meat mixture.
Bake, uncovered, at 400° for 15-20 minutes or until a toothpick inserted into cornbread layer comes out clean. Meanwhile, prepare country gravy mix according to package directions; serve with casserole.