Preheat your oven to 400F (200F). Slice the butternut squash in half with a very sharp knife.
Scoop the seeds out of the butternut squash with a spoon. Then lightly brush oil on each butternut squash halve and season with salt and pepper.
Lay the butternut squash, cut side down on a baking sheet and bake for 40-45 minutes.
While the butternut squash is cooking, add the sausage to a saute pan on medium heat. Use a spatula to break up the sausage and cook until it's just browned.
Add the onions, garlic and baby spinach to the pan and stir for 2-3 minutes, or until the spinach is wilted. Then add the apple, sage and rosemary and cook for another 2-3 minutes, or until the apple has softened slightly.
Turn off the heat and stir in the cranberries and pecans.
When the butternut squash halves are cooked through, remove them from the oven, flip them over and remove some of the flesh to make room for the filling.
Fill the butternut squash with the apple sausage filling.
Turn the top broiler on the oven and bake the filled butternut squash for 5 minutes, or until they're golden on top. Serve immediately.