Add sausage, Italian seasoning, thyme, and red pepper flakes to a large saucepan. Cook over medium heat, regularly stirring to break the sausage.
Once the sausage has released juices and is half cooked, add 1 cup of uncooked orzo and minced garlic, and cook, constantly stirring, for about 2 minutes on medium heat to brown the orzo.
Add the 5 cups of chicken stock, maple syrup, and cubed butternut squash, stir well, cover with the lid, bring to a boil, reduce to simmer, and cook for about 5 or 10 minutes until the orzo and butternut squash are cooked.
Add spinach to the soup, cover with the lid and let it wilt on low heat, stir occasionally.
Once the spinach has wilted, remove the soup from the heat and add heavy cream. Stir everything and season with salt and pepper. Add more chicken stock (or water), if the soup is too dense. Add more red pepper flakes, if you like. Top with Parmesan cheese (shaved, shredded, or grated) and fresh thyme.