Make the pasta

1. Prepare pasta al dente according to package directions.  Just before pasta is done, reserve 2 cups of the salted pasta water.

Make the sauce

1. In a large saute pan, heat the olive oil.  When oil is hot, saute the rosemary sprig and sage leaves until crispy.  Remove from oil to a paper towel.  Reserve.
2. Add the sausage to the hot oil.  Cook until done.  Drain any excess fat.
3. To the sausage, add the pumpkin purée, half-and-half, garlic, nutmeg, spinach, Parmesan, Cider Vinegar.  Stir until bubbly, adding reserved pasta water as  necessary. (I ended up adding 1 1/2 cups of the reserved water.)
4. Simmer the sauce an additional 2-3 minutes until heated through.  Add cooked pasta.  Add additional reserved water as needed.  Important: Test to see if you need more salt, you may need to salt generously.  Transfer to serving dish. Top with reserved herbs, chopped if desired.
5. Add red pepper flakes and additional Parmeggiano-Reggiano at table, as desired.