Cook penne pasta according to package, drain and let cool completely.
Grill chicken breasts, let cool slightly then chop into bite-sized pieces.
In a large bowl, toss together the pasta, chicken, romaine, cucumber, carrots, green onion, tomatoes, Parmesan and croutons.
Drizzle in desired amount of Caesar dressing and toss to coat everything evenly.
For best flavor, let the salad chill for 15-20 minutes before serving to allow flavors to meld.
Garnish with extra Parm and croutons before serving if desired.