Toss shrimp with Cajun seasoning and black pepper. Set aside.
Boil water, cook fettuccine to al dente, drain, and set aside.
Heat 1 tbsp olive oil in a skillet over medium-high. Sauté shrimp for 2–4 minutes, flipping halfway. Remove and set aside.
In the same skillet, add a bit more oil if needed and cook sausage slices for 4–5 minutes until browned. Remove and set aside.
Add more oil if necessary. Sauté onions, garlic, and thyme for about 5 minutes until fragrant and softened.
Add chicken broth, heavy cream, crushed tomatoes, and Worcestershire. Stir and bring to a simmer.
Add Cajun seasoning, sugar, garlic powder, onion powder, oregano, cayenne (if using), smoked paprika, and black pepper. Simmer for 5 minutes.
Stir in Parmesan (or Parmesan rind) and simmer for another 5 minutes until smooth and creamy.
Toss cooked pasta and sausage into the sauce. Heat for 2–3 minutes. Add shrimp, stir well, and remove from heat.
Top with fresh parsley, extra Parmesan, and cracked black pepper. Serve hot and enjoy!