Boil rotini pasta in salted water according to package directions until al dente.

Drain pasta and rinse immediately with cold water to stop the cooking process and remove excess starch.

In a small mixing bowl, whisk together the Italian dressing and the dill pickle juice until emulsified.

In a large mixing bowl, combine the cooled pasta, tomatoes, olives, bell pepper, pepperoni, mozzarella, and red onion.

Pour the dressing mixture over the salad components and toss thoroughly to ensure even coating.

Sprinkle with dried oregano and fresh parsley, then toss once more.

Refrigerate for at least 30 minutes to allow the flavors to meld before serving.