Bring 2 quarts water to a boil. Add noodles; cook 8 minutes. Add broccoli, cauliflower, and carrots; cook 3 minutes. Drain and keep warm.
Place cream cheese and next 4 ingredients in a food processor, and process until smooth.
Place pasta mixture in a large bowl. Add cream cheese mixture, and toss gently. Sprinkle with Parmesan cheese, onions, and pepper.