Boil a large pot of salted water and cook 16 oz of spaghetti until al dente. Reserve 0.5 cup of pasta water before draining.

In a food processor, combine 2 cups fresh basil, 0.5 cup toasted walnuts, 0.5 cup grated Parmesan, 2 garlic cloves, and 0.5 tsp salt. Pulse until finely chopped.

While the processor is running, slowly drizzle in 0.5 cup of extra virgin olive oil until a smooth green sauce forms.

Toss the cooked spaghetti with the blended sauce, adding splashes of the reserved pasta water to reach your desired consistency. Serve immediately.