Cook the rotini pasta according to package instructions until al dente. Drain and rinse under cold water to cool.
In a large mixing bowl, combine the cooled pasta, cherry tomatoes, mozzarella balls, and chopped basil.
In a separate small bowl, whisk together the pesto sauce, olive oil, balsamic vinegar, salt, and pepper.
Pour the dressing over the pasta salad and toss gently to combine until everything is evenly coated.
Taste and adjust seasoning if necessary.
Chill the pasta salad in the refrigerator for at least 30 minutes before serving to allow the flavors to meld.
Serve chilled, garnished with grated Parmesan cheese if desired.