1. Preheat the oven to 400° F. 

2. Prepare the butternut squash. Slice each squash in half lengthwise and use a spoon to scoop out the seeds and fleshy strands tangled with the seeds.

3. Place squash halves cut-side up on a baking sheet (line with parchment for easy clean up). Drizzle the cut sides of the squash halves with olive oil and rub the oil into the squash and season generously with salt and pepper. Flip the squash halves over so the cut sides are on the baking sheet and roast for 40-50 minutes, or until the squash is tender (use a sharp knife to poke the thickest area of the squash; it should be soft and the knife should easily cut the squash). 

4. While the squash are roasting, dice the onion, carrot, and celery and make the sausage filling. Place a large skillet over medium-high heat and add the olive oil; once hot, add the diced onion, carrot, and celery, and cook, stirring frequently, until the onion is translucent and the vegetables are soft, about 6-8 minutes.

5. Move the onion mixture to the side of the skillet to make room for the sausage. Add the sausage to the center of the skillet and cook, breaking it apart as it cooks, until it’s completely cooked through, about 15 minutes.  Mix the onion mixture into the sausage and cook an additional 5 minutes, or until the sausage is lightly browned. 

6. Add the Italian seasoning and stir to combine. Add approximately half of the baby spinach, cover, and let the spinach wilt for 2-3 minutes. Give it a stir and repeat the process, adding the remaining spinach, covering, and wilting. Once all of the spinach is wilted, stir in the cranberries and chopped pecans and mix everything together well. Remove from the heat, cover, and set aside until you are ready to assemble the squash.

7. When the squash is cooked, remove it from the oven and turn so the halves are cut-side up.

8. Let it cool slightly (about 5 minutes). Using a large spoon, scoop out some of the flesh in the squash to make room for the stuffing, leaving a one-inch border along the sides and in the bottom. If necessary, warm the sausage filling and then divide it among the four squash halves. Slice each one in half crosswise and serve immediately. Note: Refrigerate or freeze the squash you removed to make room for the stuffing and serve as a side dish with another meal.