Preheat the oven to 400°F. Line a large baking sheet with parchment paper. Add the Brussels sprouts and drizzle with olive oil. Sprinkle with salt and pepper. Toss with your hands to coat. Arrange the sprouts cut sides down. Roast for 20-25 minutes until tender.
While the sprouts roast, prepare the quinoa. Combine the quinoa with the water in a pot over high heat. Bring to a boil, then reduce heat to low, cover, and cook until the water is absorbed, 12-15 minutes. Remove from heat and let stand for 5 minutes. Transfer the quinoa to a bowl and fluff with a fork. Cool for 10 minutes.
Add the chickpeas, roasted Brussels sprouts, spinach, and cranberries. Toss gently to combine. Add the lemon juice, honey, and salt and pepper, to taste. Add the goat cheese (if using) and toss gently to combine. Transfer to a serving bowl and top with the parsley. Serve warm.