Prepare the chicken: Slice the chicken breasts in half lengthwise so they are an even thickness. Season with Cajun seasoning, garlic powder, paprika, salt, and black pepper.

Cook the chicken: Heat olive oil in a pan over medium high heat and cook the chicken for 4-5 minutes per side until golden. Remove from the pan and slice into strips.

Make the garlic butter: Mix softened butter with garlic, parsley, and salt until combined. Spread onto the cut side of the bread.

Make the Cajun sauce: In a pan, sauté the chopped onion for 1-2 minutes until soft. Add the garlic and cook for 30-60 seconds until fragrant. Pour in the cream, Parmesan, Cajun seasoning, paprika, chili flakes, salt, and pepper. Simmer for 3-4 minutes until slightly thickened.

Assemble and cook: Spread garlic butter on the bread, spoon over a layer of Cajun sauce, sprinkle mozzarella, then add sliced chicken. Drizzle a little more sauce on top and save the rest for dipping. Cook in the air fryer at 355°F / 180°C for 8-10 min or in the oven at 375°F / 190°C for about 20 min, until the cheese is melted and bubbly. Rest 1-2 min, top with chopped parsley, and serve with the remaining sauce.