Bring a large pot of salted water to a boil. Cook pasta according to package directions until al dente. Drain and rinse under cold water to stop cooking. Set aside.
While pasta cooks, make the pesto: In a food processor, combine basil, pine nuts, Parmesan, and garlic. Pulse while slowly drizzling in olive oil until smooth. Season with salt and pepper.
In a large bowl, toss the cooled pasta with the pesto until every piece is well coated.
Gently fold in the cherry tomatoes and mozzarella pearls (if using).
Taste and adjust seasoning with more salt or pepper if needed. Garnish with fresh basil leaves.
Serve at room temperature or chilled. Enjoy!