Preheat the oven to 425 degrees.
Arrange the butternut squash and onion on an aluminum foil-covered baking sheet and drizzle with 1 tablespoon olive oil. Season with salt and pepper and 1/4 teaspoon cayenne and toss to combine. Roast for 30 minutes or until tender and just beginning to brown.
Meanwhile, steam the spinach for 1-2 minutes until bright green and slightly wilted. Drain and squeeze out any excess water.
In a large bowl combine the squash, onion, spinach, dried cranberries, quinoa, and the remaining tablespoon of olive oil. Season with salt and pepper to taste. Serve warm or at room temperature.
(NOTE: This is also really delicious with toasted pine nuts!)