Cook the pasta in boiling salted water until al dente, then drain and set aside.
Heat olive oil in a large skillet over medium heat, then add sliced smoked sausage, cooking until browned and fragrant, about 5 minutes.
Add minced garlic to the skillet and sauté until fragrant—about 30 seconds—stirring continuously to prevent burning.
Pour in the heavy cream and stir in Cajun seasoning, bringing the mixture to a gentle simmer. Let it thicken slightly, about 3–4 minutes.
Stir in grated Parmesan cheese and chopped fresh herbs, mixing until the cheese melts and the sauce is creamy and vibrant.
Add the cooked pasta to the skillet, tossing to coat the noodles evenly with the savory sauce. Season with salt and pepper to taste.
Cook for another minute or two, allowing the flavors to meld and ensuring the pasta is heated through.
Serve the Mardi Gras Pasta hot, garnished with extra herbs or Parmesan if desired, and enjoy the colorful, flavorful dish.