Secure the lid and set the Pressure Release to Sealing. Select the Manual or Pressure Cook setting and set the cooking time for 6 minutes at High pressure. (The pot will take about 15 minutes to come up to pressure before the cooking program begins.)
To make the sauce: While the pasta is cooking, combine the cashews, water, nutritional yeast, lemon juice, garlic, mustard, Tabasco, salt, and cayenne in a blender. Blend at high speed for about 1 minute, until smooth, scraping down the sides of the blender halfway through, if necessary. Taste for seasoning, adding more salt and/or cayenne, if needed. You can also add an extra splash of water, if you prefer a thinner sauce.
When the cooking program ends, let the pressure release naturally for 5 minutes, then move the Pressure Release to Venting to release any remaining steam. Open the pot and stir in the sauce.
Spoon the macaroni into bowls and serve immediately.