Cook macaroni to the al dente stage according to package directions.
Soak the cashews for 4 hours or overnight. Drain.
In a high-speed blender, blend all ingredients until smooth.
Pour sauce into a pan. Cook for 3-4 minutes over medium-high heat, stirring constantly. Sauce will thicken. Remove from stove.
Mix the pasta and sauce. Adjust the salt and serve.
Garnish with red chili flakes (optional)