Throw all of your ingredients (except the pasta) into a blender and blend on high speed until smooth and creamy.
Get your water boiling in a big pot and salt it well. Cook your macaroni until al dente. Drain, reserving some pasta water for thinning the sauce out later.
Put your cooked pasta back into the empty cooking pot, and pour the sauce in. Place over a very low heat and stir until the sauce starts to thicken and coat the pasta. It should start to look stringy and cheesy. Add a little pasta water if needed to thin the sauce out if it gets too thick. Turn the heat off. Taste and add extra salt etc. if you think it needs it! Serve asap. I love to serve this with a big sprinkle of cashew (or almond) parmesan.