Start by boiling a large pot of salted water over high heat. Add 12 ounces of rotini pasta and cook according to package instructions, typically about 8-10 minutes, until al dente. Once cooked, drain the pasta in a colander and rinse it under cold water for 30 seconds.

In a spacious mixing bowl, blend together 1 cup of mayonnaise, ½ cup of sour cream, and ½ cup of Italian dressing. Stir until the mixture is smooth and well combined.

Gently fold the cooled rotini pasta into the dressing mixture, then add in the shredded Parmesan cheese, diced cucumbers, halved cherry tomatoes, diced red onion, sliced black olives, diced red bell pepper, and chopped fresh parsley. Stir carefully to combine.

Sprinkle some salt and freshly cracked black pepper over the pasta salad and give it another gentle fold to ensure the seasoning is evenly distributed.

Cover the mixing bowl tightly with plastic wrap or transfer the salad to an airtight container. Refrigerate the pasta salad for at least 1 hour.

Once chilled, give the salad a gentle stir before serving. Dish out portions onto plates or bowls.