Bring a large pot of salted water to a boil. Add pasta and cook until al dente, typically 8-10 minutes. Reserve 1 cup of pasta water and drain the pasta.

In a food processor, combine arugula, sun-dried tomatoes, garlic, cashews, salt, and pepper. Pulse until a coarse paste forms.

Drizzle in olive oil while blending. Gradually add reserved pasta water until desired consistency is achieved.

In the pot over low heat, combine pasta with pesto, tossing to coat evenly. Add more pasta water if needed.

Serve in bowls, garnish with extra Parmesan cheese and a drizzle of olive oil.