Heat your Dutch oven over medium-high heat. Add the sausage and cook, breaking it up with a wooden spoon, until browned and cooked through, about 6-8 minutes. Transfer to a plate with a slotted spoon, leaving the fat behind.

Reduce heat to medium. Add the onion to the pot and cook until softened and starting to turn golden at the edges, about 5 minutes. Add the garlic, tomato paste, oregano, and red pepper flakes if using. Cook, stirring constantly, until the tomato paste darkens slightly and the garlic is fragrant, about 2 minutes.

Pour in the chicken broth and crushed tomatoes, scraping up any browned bits from the bottom of the pot. Return the sausage to the pot. Bring to a boil, then reduce heat and simmer for 10 minutes to let the flavors meld.

Stir in the gnocchi and simmer until they float to the surface and are tender, about 3-4 minutes. Do not overcook or they will turn mushy.

Reduce heat to low. Stir in the heavy cream and spinach, cooking just until the spinach wilts, about 1 minute. Remove from heat and stir in the Parmesan. Taste and season with salt and black pepper as needed.

Ladle into bowls and top with torn fresh basil and extra Parmesan. Serve immediately with crusty bread.