Cook the rigatoni – Bring a large pot of salted water to a boil. Cook rigatoni until al dente. Drain and set aside, reserving 1/2 cup pasta water for later.

Cook the Cajun Garlic Butter Beef – In a large skillet, heat butter and olive oil over medium-high heat. Add ground beef and season with Cajun seasoning, garlic powder, salt, and pepper. Cook, breaking up the beef, until browned and cooked through (6–8 minutes). Add minced garlic in the last 1–2 minutes of cooking and stir until fragrant. Remove beef from skillet and set aside.

Make the Alfredo Sauce – In the same skillet, melt butter over medium heat. Add garlic and sauté for 30 seconds until fragrant. Pour in heavy cream and chicken broth, stirring gently. Add Parmesan and mozzarella, stirring until the sauce is smooth and creamy. Season with salt, pepper, and red pepper flakes if desired. Thin with reserved pasta water to reach your preferred consistency.

Combine Pasta & Beef – Toss rigatoni in the Alfredo sauce until fully coated. Return the Cajun garlic butter beef to the skillet and fold gently to combine.

Serve & Garnish – Plate the creamy rigatoni topped with Cajun beef. Garnish with fresh parsley, extra Parmesan, and a light sprinkle of Cajun seasoning.