In a large pot over medium heat, cook the crumbled spicy Italian sausage until browned, stirring regularly to break it apart. Sprinkle in the Italian seasoning and red pepper flakes for added warmth.
Once the sausage is nearly cooked through, stir in the minced garlic and continue to sauté for an additional minute until fragrant.
Add the diced butternut squash and pour in the chicken broth. Bring this mixture to a gentle boil, then reduce the heat and let it simmer for about 10 minutes, or until the squash is tender.
Stir in the uncooked orzo and let it cook for 5-7 minutes until al dente, stirring occasionally to prevent sticking.
Finally, add the spinach and give it a good stir, allowing it to wilt into the soup. Off the heat, gently mix in the heavy cream to give the soup that creamy texture. Adjust seasoning with salt and pepper to taste.
Serve hot, topped with grated Parmesan cheese and additional thyme leaves for an aromatic finish.