In a large pot of salted water, cook the spaghetti pasta according to the package instructions. Once done, reserve ½ cup of pasta water and drain the remaining water; set aside.

Pat dry the shrimp with a kitchen towel and season them with Cajun seasoning, garlic powder, and salt.

Meanwhile, heat a large skillet with oil over medium heat. Once the oil is heated, add the shrimp and cook for 4-5 minutes until the shrimp turns pink. Transfer the cooked shrimp to a plate and set aside.

To the same skillet, add the butter. Once the butter is melted, add the minced garlic and chopped onion. Sauté for 2-3 minutes.

Stir in the chicken broth and deglaze the skillet, allowing the broth to simmer for a couple of minutes.

Add the lemon juice along with heavy cream. Let the sauce simmer for 4-5 minutes.

Add the cooked pasta and Parmesan cheese to the skillet and toss with the shrimp and sauce for 2 minutes. If needed, add the reserved pasta water and toss it.

Finally, sprinkle some freshly chopped parsley, garnish with lemon wedges, and serve the Cajun shrimp scampi while it is still warm.