Step 1: Cook the Pasta : Preheat oven to 375°F (190°C). In a large pot of salted boiling water, cook the pasta until al dente (1–2 minutes less than package directions). Drain and set aside.

Step 2: Prepare the Sauce and Chicken :In a large bowl, combine the cooked pasta, marinara sauce, cubed chicken, Italian seasoning, and a pinch of salt and pepper. Stir in half of the mozzarella, half of the Parmesan, and chopped basil.

Step 3: Assemble the Casserole :Lightly grease a 9x13-inch baking dish. Pour the pasta mixture into the dish and spread evenly. Sprinkle the remaining mozzarella and Parmesan cheese on top.

Step 4: Add the Crunchy Topping : In a small bowl, mix panko breadcrumbs with melted butter and Parmesan. Sprinkle evenly over the top of the casserole for a golden, crispy finish.

Step 5: Bake : Bake uncovered for 25–30 minutes, until bubbly and golden brown. For extra crispiness, broil for 1–2 minutes at the end.

Step 6: Garnish and Serve : Let the dish cool for 5 minutes before serving. Garnish with fresh basil and additional Parmesan if desired.