In a large skillet heat olive oil over medium high heat. Add sausage, garlic, and onion. Sauté until the onions are soft, and the sausage is starting to brown; 5-7 minutes.
Add tomatoes, Italian seasoning, salt, pepper, half and half, and Parmesan cheese. Stir until everything is well combined. Bring to a boil, reduce heat to simmer for 5 minutes. Stir in spinach, until wilted.
Add drained pasta, stirring to combine.
Serve topped with additional Parmesan cheese if desired.