Bring a large pot of salted water to a boil and cook the refrigerated cheese tortellini according to package directions; drain and set aside.
Heat 1 tablespoon of olive oil in a large nonstick skillet over medium-high heat. Add the shrimp, sprinkle with Cajun or Creole seasoning, and cook just until pink, about 1–2 minutes per side; remove the shrimp to a plate (they will finish cooking later).
Add the remaining 1 tablespoon olive oil to the skillet. Add the sliced smoked sausage, diced onion, and diced red bell pepper and cook, stirring occasionally, until the sausage is browned and the vegetables are soft, about 5 to 7 minutes.
Add the minced garlic to the pan and cook, stirring, for about 1 minute until fragrant.
Reduce the heat to medium, add the butter, heavy cream, dried thyme, and optional cayenne pepper, and simmer gently for about 5 minutes until the sauce slightly thickens.
Stir in the grated Parmesan until melted. Return the cooked shrimp to the skillet and heat through; taste and season with salt and pepper if needed.
Add the drained tortellini to the sauce and toss until evenly coated. Sprinkle with chopped parsley and serve immediately.