TOSS shrimp with salt, pepper, Cajun seasoning, and oregano.
HEAT a large skillet over medium heat and drizzle pan with olive oil.
COOK shrimp in a skillet for 2 minutes. Flip and cook for another 1–2 minutes, then set shrimp aside. Add more olive oil and smoked sausage. Cook until caramelized for about 4–5 minutes; set aside.
COOK pasta until al dente in salted boiling water.
ADD olive oil, onion, red bell pepper, Cajun seasoning, brown sugar, and a pinch of salt in the pan on medium heat. Sauté until onion and peppers soften. Then add garlic and cook for about 30 seconds.
ADD crushed tomatoes, chicken broth, and heavy cream, and bring to a simmer, stirring every few minutes.
ADD parmesan and stir while simmering. Then add cooked pasta and smoked sausage; heat and stir for 2–3 minutes. Add the shrimp, salt, and pepper, and garnish with red pepper flakes.