Preheat your oven to 400°F (200°C). This temperature will allow the squash to roast evenly and develop a nice caramelization.

Cut the acorn squash in half lengthwise using a sharp knife. Be careful as the skin can be tough. Scoop out the seeds and stringy bits with a spoon.

Drizzle the inside of each squash half with olive oil and sprinkle with salt and black pepper. This will enhance the flavor and help with roasting.

Place the squash halves cut-side down on a baking sheet lined with parchment paper. This will help them roast evenly and prevent sticking.

Roast in the preheated oven for about 25-30 minutes, or until the flesh is tender when pierced with a fork.

While the squash is roasting, combine the rinsed quinoa and vegetable broth in a medium pot. Bring to a boil over medium-high heat.

Once boiling, reduce the heat to low, cover, and simmer for about 15 minutes, or until the quinoa is fluffy and the liquid is absorbed.

In a mixing bowl, combine the cooked quinoa, dried cranberries, chopped walnuts, ground cinnamon, ground nutmeg, chopped spinach, maple syrup (if using), salt, and black pepper. Mix well to combine all the flavors.

Once the acorn squash is roasted and tender, remove it from the oven and carefully flip the halves over so the cut side is facing up.

Spoon the quinoa mixture into each squash half, packing it slightly to ensure it holds together. Be generous with the stuffing!

Return the stuffed squash to the oven and bake for an additional 10-15 minutes, until the stuffing is heated through and slightly golden on top.

Remove the stuffed acorn squash from the oven and let it cool for a few minutes before serving. This will help the flavors meld together.

Serve warm, garnished with additional walnuts or a drizzle of maple syrup if desired. Enjoy your delicious and nutritious stuffed acorn squash!