In a medium saucepan, bring vegetable broth to a boil. Stir in quinoa, reduce heat to low, cover, and simmer for about 15 minutes until all liquid is absorbed. Remove from heat and let it sit, covered, for 5 minutes before fluffing with a fork.
Preheat your oven to 400°F (200°C). Spread cubed butternut squash on a baking sheet, drizzle with olive oil, and season with salt and pepper. Roast for 20 to 25 minutes, turning halfway through, until tender and slightly caramelized.
In a small bowl, whisk together olive oil, apple cider vinegar, maple syrup, Dijon mustard, salt, and pepper until smooth. Taste and adjust seasoning as needed.
Place fresh spinach in a large mixing bowl. Add warm quinoa on top. The gentle heat will slightly wilt the spinach, making it tender but still bright green.
Toss in roasted squash, apple slices, cranberries, and pecans. Drizzle with the maple vinaigrette and gently mix until everything is well coated.
If using feta, sprinkle it over the salad just before serving for a creamy, tangy contrast. Serve immediately or store in the refrigerator for later.