Bring a large pot of salted water to a boil and cook the pasta to al dente, according to package instructions. Reserve 1 cup of the pasta water, drain pasta and set aside.
Heat a large, deep skillet over medium-high heat. Add oil to the skillet and brown the sausage. Transfer sausage to a paper-towel-lined plate and set aside.
Add garlic and shallot. Sauté 3 to 5 minutes until translucent. Add wine to the pan and reduce by half, about 2 minutes. Add pumpkin, broth and 1 tablespoon sage and stir to combine.
Return sausage to pan, reduce heat and stir in cream. Season the sauce with the cinnamon and nutmeg, and salt and pepper to taste. Simmer mixture 5 to 10 minutes to thicken sauce. Add the cooked pasta to the pan and gently toss to combine. Thin the sauce with a bit of the reserved pasta water as needed if it seems too thick. Season with salt and pepper.
Serve immediately, topped with Parmesan cheese and sage leaves.
