Cook the butternut squash. Heat 1 tablespoon olive oil in a large skillet over medium heat. Add the cubed butternut squash, season with a little salt and pepper, and cook for about 10–12 minutes, stirring occasionally, until fork tender and lightly browned. Add a splash of water and cover for a few minutes if the squash needs help softening. Remove the squash and set aside.
Brown the sausage. In the same skillet, add the Italian sausage. Break it apart with a spoon and cook until browned and cooked through. Drain excess grease if needed.
Make the sauce. Add the remaining tablespoon of olive oil if the skillet is dry. Stir in the garlic, Italian seasoning, and sage. Cook for about 30 seconds. Pour in the chicken broth and heavy cream. Stir and bring to a gentle simmer.
Add the Parmesan. Stir in the Parmesan cheese and nutmeg, if using. Let the sauce simmer for 2–3 minutes until slightly thickened.
Meanwhile, cook the tortelloni or tortellini according to package directions. Drain and gently add to the skillet.
Stir in the cooked butternut squash and fresh spinach. Gently toss everything together until the spinach wilts and the tortelloni is coated in the creamy sauce.
Top with extra Parmesan cheese, cracked black pepper, and a little fresh sage.