Cook the tri-color rotini pasta in salted boiling water for 8-10 minutes until al dente. Drain and rinse with cold water.

In a large mixing bowl, combine the pasta with halved cherry tomatoes, sliced pepperoni, diced red onion, and chopped green bell pepper.

Fold in cubed mozzarella and grated Parmesan cheese, along with sliced olives, mixing thoroughly.

In a separate bowl, whisk together olive oil, red wine vinegar, Italian seasoning, garlic powder, salt, pepper, and red pepper flakes.

Pour the vinaigrette over the salad and toss gently to coat all ingredients.

Cover and refrigerate for at least 1 hour before serving.