Brush the inside of the squash halves with 1 tablespoon of olive oil and 1 tablespoon maple syrup and season with salt and pepper. Place these, cut side down, on a greased baking sheet and roast for 30–40 minutes in a 400° oven. The squash halves are done when a fork passes easily through skin and flesh. Remove them from the oven, turn them over with a spatula and set aside.
While the squash is roasting, prepare the stuffing.
Heat 2 tablespoons of oil in a large skillet and cook the shallot and parsnips over medium heat for about 10 minutes or until the parsnips are soft. Add the apple and cook for 5 more minutes.
Once the pieces of apple are tender, remove the mixture from the heat. Mix in the spinach, sage and cooked quinoa and season with salt and pepper. Spoon the stuffing into the cooked squash halves, top with cheese (if desired) and return them to the oven for 10 minutes or until the cheese is melted.