Bring a large pot of salted water to a rolling boil. Meanwhile, toast pine nuts in a dry skillet over medium heat until golden and fragrant, about 3 minutes, stirring constantly.
Cook the pasta in the boiling water according to package instructions until al dente, about 8-10 minutes. Drain the pasta in a colander, reserving about 1/2 cup of pasta water, and set aside.
Place the fresh basil, toasted pine nuts, nutritional yeast, lemon juice, and garlic in your blender. Pulse a few times to combine, then slowly drizzle in the olive oil while blending until the pesto is smooth, bright green, and creamy. Taste and season with salt and pepper as needed.
Transfer the cooked pasta to a large mixing bowl. Add the pesto and toss thoroughly to coat each strand evenly. Use a splash of the reserved pasta water if the sauce feels too thick, stirring until silky.
Check the pasta for doneness: it should be coated in a vibrant green, fragrant pesto with a silky texture. Adjust seasoning if needed by adding more salt, pepper, or lemon juice.
Serve immediately, garnished with extra basil leaves or a drizzle of olive oil if desired. Enjoy the fresh, herbaceous flavors in every bite!
