Heat oven to 375. Spray a 2-1/2-quart casserole dish w/ cooking spray. In bowl, stir together alfredo sauce and 2 cups water, add pepper. Pour 1 cup sauce into casserole dish. Arrange 1/2 of the tortellini over sauce. Sprinkle w/ broccoli. Pour 1-1/2 cups sauce over broccoli. Repeat layering remaining tortellini and sauce. Bake, uncovered 45 min. Heat broiler. In small bowl, stir together bread crumbs, garlic powder and oil. Sprinkle crumbs over casserole. Place casserole under broiler for 2 min.