Bring a large pot of salted water to boil and add the rotini pasta. Cook according to package instructions until al dente, usually around 8-10 minutes, then drain and let cool.

In a large mixing bowl, combine the cooled pasta, halved cherry tomatoes, cubed mozzarella cheese, halved pepperoni, diced green bell pepper, and drained black olives. Stir gently to avoid crushing the ingredients.

Pour the Italian dressing over the pasta mixture, then toss everything together carefully, ensuring each piece of pasta is well coated.

Sprinkle the shredded Parmesan cheese over the top of the salad. Gently mix again to distribute the cheese throughout the salad.

Cover the pasta salad with plastic wrap and refrigerate for at least 30 minutes to allow the flavors to meld together beautifully before serving.