Slice smoked sausage into quarter-inch rounds. Heat olive oil in a large skillet or Dutch oven over medium-high heat. Add the sausage and cook for 4-5 minutes until golden brown on both sides with crispy edges. Remove to a plate and set aside.

In the same pot with the flavorful drippings, add diced bell peppers and onions. Sauté for 3-4 minutes until vegetables soften and onions become translucent.

Sprinkle Cajun seasoning and garlic powder over the vegetables, stirring for 30 seconds until fragrant.

Pour in chicken broth and bring to a simmer. Add pasta directly to the pot, stirring to ensure all pieces are submerged. Cook for 8-10 minutes, stirring occasionally to prevent sticking, until pasta is al dente and most liquid has been absorbed. Add broth quarter cup at a time if pasta seems dry.

Reduce heat to medium-low. Stir in heavy cream and Parmesan cheese, mixing until cheese melts completely and creates a creamy sauce. Return browned sausage to pot and mix well. If using spinach, add now and stir until wilted, about 1 minute.

Taste sauce before adding any salt, since Cajun seasoning and sausage contribute saltiness. Adjust seasoning with black pepper or cayenne if desired.

Remove from heat and let rest for 2-3 minutes to allow sauce to thicken slightly. Garnish with fresh parsley and extra Parmesan cheese. Serve immediately.