Cook the pasta in a large pot of salted boiling water until just al dente, about 8–10 minutes. Drain and set aside.
If roasting garlic, wrap a whole bulb in foil with a drizzle of olive oil and roast in a preheated oven at 180°C (350°F) for 30 minutes until soft and fragrant. Once cooled, squeeze out the roasted garlic cloves.
In a blender, combine the soaked cashews, nutritional yeast, roasted garlic, smoked paprika, lemon juice, and plant-based milk. Blend until completely smooth and creamy, about 1–2 minutes, stopping to scrape down sides if needed.
Pour the sauce into a medium saucepan and warm over medium-low heat. Stir constantly with a spatula or spoon until it begins to shimmer and thickens, about 3–5 minutes. If it becomes too thick, add a splash more plant milk to loosen it.
Transfer the cooked pasta into the sauce and toss gently to coat evenly. Continue to cook for another 2 minutes, allowing the flavors to meld and the sauce to cling to the noodles.
Remove from heat and let sit for a minute to settle. Serve hot, garnished with a sprinkle of smoked paprika or fresh herbs if desired, for an inviting, cheesy look.