In a medium bowl, combine mayonnaise, red wine vinegar, grated garlic, dried oregano, black pepper, and red pepper flakes. Whisk until smooth and well blended. Cover and refrigerate the dressing while preparing the salad.

Bring a large pot of salted water to a boil. Add campanelle pasta and cook until al dente, about 8-10 minutes. Drain and rinse under cool water, then set aside to cool.

Soak sliced red onion in a bowl of ice water for 10-15 minutes. Drain and pat dry with paper towels.

In a large mixing bowl, add cooled pasta, mozzarella pearls, provolone cheese, diced salami, pepperoni, drained red onions, sliced pepperoncini, thinly sliced romaine lettuce, halved cherry tomatoes, and sliced fresh basil. Gently toss to combine.

Pour dressing over the pasta mixture, sprinkle with grated Parmesan cheese, and toss until well coated. Adjust seasoning with salt and pepper if desired.

Transfer the salad to a serving dish. Garnish with additional Parmesan cheese, basil leaves, and black pepper. Chill before serving for the best flavor.