Bring a large pot of salted water to a boil, then add your pasta and cook until just al dente, about 8-10 minutes. Drain, reserving a cup of pasta water, and set aside.
While the pasta cooks, place toasted pine nuts in a dry skillet over medium heat. Toast, stirring frequently, until golden and fragrant, about 3-4 minutes. Remove from heat and let cool slightly.
In a blender or food processor, combine fresh basil, toasted nuts, chopped garlic, lemon juice, nutritional yeast, and a pinch of salt and pepper. Blend while slowly drizzling in olive oil until the mixture is bright green and smooth, adjusting with more oil or water as needed.
Transfer the cooked pasta back to the pot or a mixing bowl. Add a few spoonfuls of pesto and toss gently to coat the noodles evenly. If the mixture feels thick, loosen it with a splash of the reserved pasta water, stirring until silky and well combined.
Squeeze a little extra lemon over the pasta, then taste and adjust seasoning with more salt, pepper, or lemon if needed. Toss again to distribute evenly.
Serve immediately, garnished with additional herbs or nuts if desired. Enjoy your vibrant, herby vegan pesto pasta!
