Bring a large pot of salted water to boil. Add gnocchi and cook according to package directions until they float to the surface (2-3 minutes for fresh gnocchi). Drain and set aside, reserving 1/2 cup pasta water for later if needed.

Heat olive oil in a large skillet over medium-high heat. Add crumbled sausage and cook for 5-7 minutes, breaking it apart with a wooden spoon until golden brown and no longer pink.

Push sausage to one side of the pan and add diced onion to the empty space. Cook for 3-4 minutes until softened and translucent. Add minced garlic and sun-dried tomatoes, stirring everything together. Cook for another minute until fragrant.

Pour in chicken broth, scraping up any browned bits from the bottom of the pan. Add heavy cream and Italian seasoning, bringing the mixture to a gentle simmer. Let it bubble softly for 2-3 minutes to thicken slightly.

Stir in the cooked gnocchi, tossing gently to coat with the creamy sauce. Add fresh spinach and Parmesan cheese, folding everything together until the spinach wilts and the cheese melts completely. Season with salt and pepper to taste. If the sauce seems too thick, add a splash of the reserved pasta water.