Cook pasta in a large pot of boiling water for 8-10 minutes until al dente, then drain.
While the pasta cooks, in a separate pan heat 1 tablespoon of olive oil over medium heat. Season shrimp with salt and pepper and 1 teaspoon of Cajun seasoning. Add shrimp and cook for around 2 minutes then flip and cook for around 2-3 minutes until cooked through, then transfer to a plate and set aside.
Wipe the pan, then heat butter over medium heat until melted. Add garlic and cook until fragrant, about 30-45 seconds.
Add cream and 1 tablespoon of cajun seasoning and stir to combine then bring to low simmer.
Working in batches, add parmesan cheese, stirring frequently, until each batch is melted. Continue cooking for 1-2 minutes until sauce is thickened and coats spoon.
Add salt and pepper to taste then add cooked pasta and stir or toss to combine until the pasta is well coated. Serve pasta in bowls and top with cooked shrimp and additional parmesan cheese.
Notes
For less spice reduce Cajun seasoning added to the sauce to 1 or 2 teaspoons, for more spice add around ½ tsp of cayenne pepper.