In large bowl, combine Alfredo pasta sauce, water, basil and pepper; mix well with wire whisk. Stir in tortellini and broccoli. Spoon into ungreased 11x7-inch (2-quart) glass baking dish. Cover with foil; refrigerate at least 8 hours or overnight.
Heat oven to 350°F. Bake covered for 45 minutes.
Uncover baking dish; stir well. Sprinkle croutons evenly over top. Cover; bake an additional 15 to 20 minutes or until bubbly and thoroughly heated.