Cook pasta according to package directions, drain, and set aside.
Fill a large pot with water, and bring to a boil. Add in the chopped cauliflower and carrots. Cook for 10-15 minutes, or until softened. Drain, and add to a food processor or high speed blender.
Add in the oil, water, lemon juice, nutritional yeast, onion powder, garlic powder, salt and pepper. Process/blend until smooth.
Add cheese sauce to your pot full of drained pasta and mix well.