Bring a large pot of salted water to a boil. Add 16 ounces rotini pasta and cook according to package instructions until al dente. Drain and transfer to a serving bowl.
Add 12 ounces salami, 2 pints cherry tomatoes, 1 1/2 cups orange bell pepper, 12 ounces sliced pepperoncini, 1 cup black olives, ½ cup red onion, 16 ounces fresh mozzarella cheese, and ¼ cup fresh parsleyto a large serving bowl. Toss to combine.
Pour 1 cup Italian dressing over the salad and gently toss until evenly combined.
Cover with plastic wrap and chill in the refrigerator for at least 2 hours to let the flavors meld together. Serve cold.
Notes
Make ahead: Chill the pasta salad for at least 2 hours, or overnight if you have time, so the flavors can really come together.
Storage: Keep leftovers in an airtight container in the fridge for up to 4 days.
Refresh: If the pasta soaks up too much dressing as it sits, stir in a little extra Italian dressing before serving.