Cook the noodles according to package instructions, then drain and rinse with cool water. Drain and add pasta to a large bowl.
Add in ½ cup italian dressing, and mix well. Cover and refrigerate 20 minutes while preparing and slicing the olives, peppers, cheese, cucumber, and onion.
Add mini pepperoni, tomatoes, and remaining vegetables and mozzarella cheese to bowl of pasta. Add remaining italian salad dressing and gently mix, coating salad ingredients evenly. Optional: top with grated parmesan cheese and fresh parsley to serve.
Spaghetti Salad can be made up to a day ahead of time. Keep refrigerated and stir just before serving.