Bring a large pot of salted water to a boil. Add pasta and cook until al dente according to package instructions.
Drain pasta and rinse briefly under cold water to stop the cooking process and cool it down. Let it drain well and transfer to a large mixing bowl.
Add cherry tomatoes and mozzarella balls to the cooled pasta.
Add pesto and olive oil to the bowl. Toss gently with a large spoon or silicone spatula until everything is evenly coated.
Season with freshly ground black pepper to taste. Add Parmesan cheese, and toss again to combine.