Cook the pasta shells as instructed on the package, then drain and set aside. Preheat the oven to 375°F and grease a 9×13-inch baking dish.

In a large skillet over medium heat, brown the ground beef while breaking it apart and seasoning it with garlic powder, salt, and pepper.

Once the beef is fully cooked, incorporate the drained pasta, tomato soup, water, and half of the shredded cheeses into the skillet. Stir the mixture well and allow it to cook together for 2 to 3 minutes.

Transfer the combined mixture into the prepared baking dish and evenly distribute the remaining cheese over the top. Cover the dish with aluminum foil and place it in the oven to bake for 20 minutes.

Remove the foil and continue baking for an additional 10 minutes. For a golden cheese topping, activate the broiler during the final 2 to 3 minutes of baking. Serve hot and refrigerate any leftovers for up to three days.