Bring a large pot of salted water to a boil. Add the elbow macaroni and cook according to package instructions until al dente. Drain and set aside.

In a skillet, heat olive oil over medium heat. Season the chicken pieces with Cajun seasoning, ensuring they are evenly coated. Cook the chicken for 5-7 minutes, stirring occasionally, until cooked through and no longer pink in the center. Remove from heat and set aside.

In the same skillet, melt the butter over medium heat. Once melted, whisk in the flour and cook for about 1-2 minutes until it forms a paste (roux). This step is crucial for thickening the sauce.

Gradually whisk in the warmed milk, ensuring there are no lumps. Continue to whisk until the mixture thickens and bubbles, about 5-7 minutes.

Reduce heat to low and stir in the shredded cheddar and Monterey Jack cheeses until melted and smooth. Add garlic powder, onion powder, cayenne pepper, salt, and pepper to taste.

Preheat your oven to 350°F (175°C). In a large mixing bowl, combine the cooked pasta, Cajun chicken, and cheese sauce. Stir until everything is well coated.

Transfer the mixture to a greased baking dish.

In a small bowl, mix breadcrumbs with melted butter and Parmesan cheese. Sprinkle this mixture evenly over the top of the mac and cheese.

Bake in the preheated oven for 20-25 minutes, or until the top is golden brown and crispy.

Remove from the oven and let it sit for 5 minutes before serving. This allows the cheese sauce to set slightly, making it easier to serve.

Enjoy your Cajun Chicken Mac and Cheese hot, garnished with additional Cajun seasoning if desired.