Easy Dump and Bake Chicken Parmesan Casserole with Stretchy Mozzarella Step-by-step instructions

Before you start

Before you begin assembling the casserole, gather all your ingredients and equipment to ensure a smooth cooking process. Preheat your oven to 375°F (190°C) so it is perfectly hot when the dish is ready to bake. Cook the penne pasta in a large pot of salted boiling water until it is just al dente, then drain it thoroughly.

Dice the chicken breasts into uniform one-inch pieces on a dedicated cutting board, and freshly shred the mozzarella and parmesan cheeses. Having these components prepped and ready makes assembly incredibly quick and effortless.

Instructions

Assembling the Casserole

1. 1Combine Chicken, Pasta, and Marinara
   In a large mixing bowl, combine the diced raw chicken breasts, the cooked and drained penne pasta, and the entire jar of marinara sauce. Use a sturdy spoon to stir the ingredients thoroughly, ensuring every piece of chicken and pasta is completely coated in the sauce. Transfer the mixture into an ungreased 9x13-inch glass baking dish, spreading it out into an even, flat layer.
   Look for The chicken and pasta should be evenly distributed and fully submerged in the sauce.
   Tip Make sure the chicken pieces are separated so they do not clump together while baking.
2. 2Add the First Layer of Cheese
   Sprinkle half of the grated parmesan cheese and half of the shredded mozzarella cheese evenly over the top of the sauced pasta and chicken mixture. Gently press the cheese down with the back of a spoon to help it adhere to the sauce, which ensures it melts evenly into the casserole during the initial baking phase.
   Look for A light, even layer of cheese should cover most of the pasta.
   Tip Reserving half of the cheese for later prevents the top from burning during the long bake.

At the end of this phase, the raw chicken, cooked penne, and rich marinara sauce should be thoroughly combined into a cohesive, moist mixture.

When spread into the baking dish, the sauce should completely coat every element, leaving no dry pasta exposed. The initial light dusting of mozzarella and parmesan should sit evenly on top, ready to melt into the sauce as it heats.

Baking to Cook the Chicken

3. 3Cover and Bake the Casserole
   Cover the glass baking dish tightly with a sheet of aluminum foil. Place the dish in the preheated oven at 375°F (190°C) and bake for twenty minutes. This covered baking environment traps the steam, which cooks the raw chicken completely through while keeping it incredibly tender and preventing the pasta from drying out.
   Look for You should hear a gentle bubbling sound coming from inside the covered dish.
   Tip Spray the underside of the foil with nonstick cooking spray to prevent the cheese from sticking.
4. 4Verify Chicken Doneness
   Carefully remove the aluminum foil from the baking dish, watching out for hot steam. Use an instant-read meat thermometer to check the thickest piece of chicken in the center of the casserole. The chicken is safe to eat when it reaches an internal temperature of 165°F (74°C). If it has not reached this temperature, return the covered dish to the oven for an additional five minutes.
   Look for The chicken pieces should look opaque and white throughout, with no pink remaining.
   Safe temperature 165°F (74°C) internal temperature (poultry)
   Tip Always insert the thermometer probe horizontally into a piece of chicken for an accurate reading.

By the end of this phase, the casserole will be piping hot and releasing a fragrant, garlic-infused steam. The raw chicken pieces will be fully cooked, tender, and opaque throughout, having successfully reached a safe internal temperature of 165°F (74°C). The initial cheese layer will have melted completely, blending seamlessly into the bubbling marinara sauce.

Melting and Browning the Cheese

5. 5Top with Remaining Cheese
   Scatter the remaining shredded mozzarella cheese and grated parmesan cheese in a thick, uniform layer across the entire surface of the hot casserole. Return the uncovered baking dish to the oven and bake for an additional eight to ten minutes, allowing the newly added cheese to melt completely and begin to bubble.
   Look for The cheese should be completely melted and actively bubbling around the edges.
   Tip For a deeper golden-brown color, you can turn on the broiler for the last two minutes.
6. 6Rest and Serve
   Remove the casserole from the oven and place it on a heatproof wooden cutting board or trivet. Let the dish rest undisturbed for ten minutes before serving. This resting period allows the hot marinara sauce to cool slightly and thicken, ensuring the casserole holds its shape when scooped and yields perfect, stretchy cheese pulls.
   Look for The bubbling will subside, and the cheese topping will set slightly.
   Tip Garnish with freshly chopped basil or parsley right before serving for a pop of color.

At the conclusion of this final phase, the casserole will be a stunning sight. The top layer of mozzarella and parmesan will have transformed into a glossy, golden-brown blanket of melted cheese. Active, crisp bubbling sounds will rise from the edges of the dish, and the aroma of toasted cheese and rich tomato sauce will fill the room, indicating it is ready to rest.

Common mistakes

One common mistake is using completely uncooked pasta without adjusting the liquid ratio. If you do not pre-cook the penne to al dente, the pasta will absorb all the moisture from the marinara sauce, leaving you with dry chicken and hard, chalky noodles. Another frequent error is failing to cover the dish with foil during the first half of baking.

Without the foil, the moisture evaporates too quickly, causing the chicken to dry out and the cheese to burn before the poultry is cooked through. Lastly, avoid slicing the chicken into uneven pieces, which leads to some bites being overcooked while others remain dangerously raw.

How to tell it’s done

Determining the perfect doneness of this casserole involves checking both the chicken and the cheese topping. The most critical safety check is verifying that the chicken has reached an internal temperature of 165°F (74°C) using a digital meat thermometer.

Visually, the chicken pieces should be firm, opaque, and white to the center. For the cheese, look for a fully melted, glossy surface with golden-brown spots scattered across the top. The edges of the casserole should be actively bubbling, and the sauce should look thick and rich rather than watery.

• Poultry: 165°F (74°C) in the thickest part