Preheat the oven to 400°F (200°C). Slice the delicata squash lengthwise and scoop out the seeds using a spoon. Brush the cut sides with olive oil and season with salt and pepper.

Place the squash halves cut-side down on a baking sheet lined with parchment paper. Roast for about 25 minutes or until the squash is tender and easily pierced with a fork.

While the squash roasts, heat a skillet over medium heat and cook the sausage until browned. Add the onion, celery, and garlic, then sauté until softened and fragrant.

Stir the cooked quinoa, dried cranberries, pecans, thyme, sage, salt, and pepper into the sausage mixture. Mix everything well and cook for another 2–3 minutes until heated through.

Remove the roasted squash from the oven and carefully flip the halves over. Fill each squash cavity generously with the prepared stuffing mixture, pressing it lightly into place.

Return the stuffed squash to the oven for 10 minutes to warm through. Garnish with fresh parsley and Parmesan cheese if desired, then serve immediately while hot.