Rinse cashews in cold water. Place in a large bowl; add water to cover by 3 in. Cover and let stand overnight.
Cook pasta according to package directions. Drain and rinse cashews, discarding liquid. Transfer to a food processor. Add 1-1/2 cups water, nutritional yeast, lemon juice and spices; cover and process until pureed, 3-4 minutes, scraping down sides as needed.
Drain pasta; return to pan. Stir in cashew mixture. Cook and stir over medium-low heat until heated through. Sprinkle with additional paprika, if desired.