Bring a large pot of salted water to a boil. Cook the pasta according to package directions until al dente. Drain and rinse under cold water to stop cooking.
While the pasta cooks, prepare the vegetables: halve the tomatoes, dice the cucumber and bell pepper, chop the onion, and slice the olives. Place them in a large mixing bowl.
In a separate bowl or jar, whisk together olive oil, red wine vinegar, Dijon mustard, garlic powder, oregano, honey, salt, and pepper until smooth and emulsified.
Add the cooled pasta to the bowl of vegetables. Pour the dressing over the top and toss until everything is evenly coated.
Fold in the mozzarella, Parmesan, and parsley. Taste and adjust seasoning if needed.
Cover and refrigerate for at least 30 minutes before serving.
Tip: If the salad seems dry after chilling, drizzle on a splash of olive oil and toss again before serving.