Place the cashews and water in a high-speed blender and blend until smooth and creamy (will take about 1 minute.)
Add the butternut squash, nutritional yeast, garlic clove, lemon juice, onion powder, nutmeg, cayenne, dijon and salt and pepper to the blender and blend until smooth and creamy. Taste and adjust seasoning if needed.
Cook the macaroni according to package directions. Reserve ¼ cup pasta water, then drain and set aside.
Pour the butternut squash “cheese” sauce into a pot and bring to a light boil on medium-high heat for 1-2 minutes until the sauce thickens slightly.
Add the macaroni and pasta water to the pot and mix everything together.
Serve immediately.
