Cook the pasta until al dente, reserving 1 cup of pasta water before draining.
Brown the sausage in a large skillet.
Add the onion and cook for 3–4 minutes, then add the garlic, sage, thyme, salt, and pepper.
Stir in the pumpkin and cook for 1–2 minutes.
Add the heavy cream and chicken broth and simmer for 2–3 minutes.
Reduce the heat and stir in the Parmesan and butter.
Add the cooked pasta and about ¼ cup pasta water, tossing until creamy.
Add more pasta water as needed.
Finish with the spinach and toss until wilted.
Top with Parmesan and cracked black pepper.
