In a medium-sized bowl, combine the shrimp with 1 tablespoon of creole seasoning and set aside.

In a large pot of salted boiling water, cook the penne to al dente according to package instructions. Drain and briefly rinse to prevent sticking.

Add the olive oil to a large saucepan or dutch oven set over medium heat. Add the shrimp and cook for 1 1/2 - 2 minutes per side, or until just cooked through. Transfer to a plate.

Add the sausage to the pan and brown on both sides, 3-5 minutes. If the bottom of the pan starts getting too brown and looks like it might burn, add a splash of water and use a spatula to scrape up the brown bits, stirring them to coat the sausage.

Add an additional drizzle of oil if needed, then the onions, celery, and bell peppers. Cook, stirring frequently, until the vegetables are tender and slightly brown, 4-5 minutes. Stir in the garlic and cook for an additional minute.

Stir in the tomatoes, tomato paste, stock, crushed red pepper, and remaining creole seasoning. Bring to a simmer over medium heat, then reduce to low and cook, stirring occasionally, for 15 minutes.

Stir in the cream, then add the shrimp and pasta back to the pot and stir until warmed through, about 2 minutes. Season with salt and pepper if desired.

If using, top with the parmesan and parsley before serving.