Step 1: In a medium bowl, toss the chicken cubes with olive oil, Cajun seasoning, garlic powder, and smoked paprika until the chicken is evenly coated. This ensures every piece has flavor.

Step 2: Heat a large skillet over medium-high heat. Add the chicken to the skillet and cook for 6 to 8 minutes, stirring occasionally, until the chicken is browned on all sides and fully cooked through. Remove the chicken from the skillet and set aside.

Step 3: While the chicken cooks, bring a large pot of salted water to a boil. Add the rigatoni and cook according to package instructions until al dente. Drain and set aside.

Step 4: Return the skillet to medium heat and melt the butter. Add the minced garlic and sauté for about one minute, stirring frequently, until fragrant but not browned.

Step 5: Sprinkle the flour over the melted butter and garlic. Whisk continuously for 1 to 2 minutes to cook out the raw flour taste and form a light roux.

Step 6: Slowly pour in the milk while whisking constantly to avoid lumps. Continue to cook and whisk for 3 to 5 minutes until the sauce thickens slightly and becomes smooth.

Step 7: Reduce the heat to low. Add the cubed Velveeta and softened cream cheese to the sauce. Stir gently and continuously until both cheeses melt completely and the sauce becomes smooth and creamy.

Step 8: Stir in the shredded mozzarella and grated Parmesan cheeses. Mix until the cheeses are fully incorporated, creating a rich, cheesy sauce. Taste the sauce and season with salt and pepper as needed.

Step 9: Return the cooked rigatoni and chicken to the skillet. Toss everything together carefully, ensuring that the pasta and chicken are evenly coated with the creamy Velveeta garlic sauce.

Step 10: Serve the dish hot. If you like, garnish with chopped fresh chives or parsley for a bright, fresh finish.