In a food processor, combine fresh basil leaves, garlic, olive oil, and Parmesan cheese. Pulse until smooth, adjusting olive oil as necessary.

Bring a large pot of salted water to boil and cook pasta until al dente, about 8-10 minutes. Reserve a cup of pasta water and drain.

In a large skillet over medium heat, add drained pasta and pour in the pesto sauce. Toss gently to coat.

Adjust seasoning with salt and pepper to taste. Serve immediately with additional Parmesan if desired.