1. Preheat oven to 425 degrees Fahrenheit. Grease two baking sheets.
2. Spread butternut squash on one baking sheet. Combine broccoli, cauliflower, and pearl onions on the second baking sheet. Spray both sheets of vegetables with cooking spray. Then sprinkle with salt and pepper.
3. Bake butternut squash for 20 minutes. Bake broccoli mixture for 10 minutes.
4. Meanwhile prepare the cranberry dressing. In a tall container, combine all dressing ingredients. Use an immersion blender to blend together. (Alternately, you can use your food processor). Do not overblend (you want some chunky pieces of cranberry to remain).
5. Drizzle dressing over roasted vegetables as soon as they come out of the oven. Serve warm.