Preheat the grill to medium-high heat.
In a bowl, combine olive oil, garlic powder, salt, and pepper. Add chicken breasts, coating them evenly with the marinade.
Allow the chicken to marinate for at least 20 minutes or up to 2 hours in the refrigerator.
Place the marinated chicken onto the preheated grill. Cook for 6-7 minutes on each side, or until the internal temperature reaches 165°F.
Remove chicken from the grill and let it rest for 5-10 minutes before slicing.
In a large bowl, toss the chopped romaine lettuce with Caesar dressing until evenly coated.
Add croutons and grated Parmesan to the lettuce mixture, and toss gently to combine.
Slice the grilled chicken and place it on top of the salad. Sprinkle additional Parmesan if desired.
