Prep and roast the squash. Preheat the oven to 425 F. Add parchment to a baking sheet.
Slice the squash lengthwise, scoop out the seeds and discard. Season it with salt, pepper or seasoning of choice.
Place the squash cut side down on the baking sheet and cook it for 40-45 minutes until a sharp knife can be easily inserted into the center of the squash.
Remove and let cool.
While squash is cooking, add onions to a dry skillet on low heat and sauté, using broth, wine or water as necessary to deglaze the pan.
Add celery and garlic. Cook for a few minutes and then add in the fresh herbs and apples. Deglaze the pan with broth, wine, or water, as needed.
Cover and simmer, stirring occasionally until the celery and apples are softened.
Add the spinach and stir and cook until it begins to wilt. Add the sausage and stir to mix. Remove the pan from the heat and add the cranberries and pecans and mix it all together.
If using two small butternuts, scoop out the flesh of the squash, leaving a 3/4-1" border around the edges and about a 2" amount of squash at the bottom.
If using one large squash, like pictured, cut off the top (neck) of the squash, scoop out the cavity leaving about 2" of squash all around.
Divide the filling and fill each cavity.
Lower the oven temperature to 375 F and place the squash back into the oven for about 10-15 minutes.