Bring a large pot of salted water to a boil. Add the spaghetti and cook according to package instructions until al dente.

Reserve 1 cup of pasta water, then drain the pasta and set aside.

In a blender or food processor, combine basil, pine nuts, parmesan cheese, minced garlic, salt, and pepper.

With the motor running, slowly drizzle in the olive oil until the mixture is smooth and creamy.

In a skillet over medium heat, combine the cooked pasta with the garlic pesto, adding reserved pasta water as needed to achieve desired consistency.

Toss well to coat the pasta evenly with the pesto. Serve immediately, garnished with additional parmesan if desired.