Cook the pasta to your liking, then rinse in cold water and drain.
Add the vegan butter to the pasta. Stir until combined.
In a blender or food processor, combine the cashews, water, nutritional yeast, minced garlic, turmeric, lemon juice, and salt and pepper to taste. Pulse on high until well blended and smooth.
Pour the cheese mixture over the pasta, then stir to combine. If the mixture is too thick, you can add a couple of tablespoons of water.
Serve topped with freshly chopped parsley if desired.