Preheat oven to 375°F.
Cut ciabatta loaf into cubes, bake until golden brown.
Make salad dressing, whisk together red wine vinegar, balsamic vinegar, maple syrup and Dijon mustard. Slowly whisk in extra virgin olive oil. Season to taste with salt and black pepper.
Place croutons and onion in the salad bowl and pour ½ cup dressing over all of it so it softens up slightly.
Place butternut squash cubes on a nonstick baking sheet. Drizzle with olive oil and season with salt and black pepper. Roast for 10 minutes.
Add shredded Brussels sprouts to baking sheet, toss together and place back in the oven for 10 minutes or until squash is cooked and Brussels sprouts are slightly crispy.
Place squash, Brussels sprouts, spinach, blue cheese, and cranberries in the serving bowl with croutons and red onion.
Pour additional dressing over salad and then gently toss together. (You may not use all the dressing).