I love a casserole that behaves like a weeknight superhero: feeds a crowd, cleans up fast, and doesn’t demand two hours of babysitting. This Skinny Chicken Parmesan Casserole does all three. It leans on pantry-friendly marinara, whole-grain penne, and simple seasoning to deliver the familiar flavors of chicken parm in an easy, layered bake.

It’s purpose-built for the evenings when you want something comforting without the heaviness. You cook the pasta, assemble everything in a single 9 x 13-inch dish, bake, add a crisp breadcrumb topping, and you’re done. The result is saucy, cheesy, and just crisp enough on top to keep everyone happy.

I test recipes until they’re practical and consistent. This version uses skim mozzarella and whole-wheat Panko to shave calories and keep texture present — no soggy middles or gummy cheese. Below you’ll find the exact ingredient list and step-by-step directions, plus tips, common errors, and freezer notes so you can make it with confidence.

What You’ll Need

Ingredients

1 pound penne pasta whole grain — holds its shape and adds fiber; cook to al dente so it doesn’t go mushy during baking.
1 jar marinara sauce 24-25 ounce jar, no sugar added — the main flavor base; choose a good-quality jarred sauce for the easiest route.
15 ounces diced tomatoes optional — adds brightness and a bit more sauce; leave out if your marinara is already juicy.
1 pound boneless and skinless chicken breasts cut into bite size pieces — bite-size pieces cook evenly in the casserole without needing pre-sautéing.
1 cup skim mozzarella cheese shredded — melts for stretch and cheesiness with fewer calories.
1/2 cup Panko bread crumbs whole wheat — gives the top crunch; whole-wheat Panko keeps the “skinny” theme.
1/4 cup grated parmesan cheese — mixes with the Panko for a savory, golden topping.
1 teaspoon Italian Seasoning optional, ground oregano — adds an herby lift; optional but nice if your marinara is plain.

Skinny Chicken Parmesan Casserole, Made Easy

Preheat the oven to 375°F. Grease a 9 x 13-inch casserole dish or spray lightly with cooking spray.
Cook 1 pound penne pasta according to the package directions until al dente. Drain and set aside.
In the prepared 9 x 13-inch casserole dish, combine the cooked pasta, 1 jar marinara sauce (24–25 oz), 1 pound boneless skinless chicken breasts cut into bite-size pieces, and 15 ounces diced tomatoes (if using). Stir until evenly combined.
Cover the casserole dish tightly with foil or a lid and bake at 375°F for 30 minutes.
While the casserole bakes, mix 1/2 cup whole wheat Panko bread crumbs, 1/4 cup grated parmesan cheese, and 1 teaspoon Italian Seasoning (if using) in a small bowl; set aside.
After 30 minutes, remove the casserole from the oven and stir in 1 cup shredded skim mozzarella cheese until evenly distributed.
Sprinkle the breadcrumb-parmesan mixture evenly over the top of the casserole. Leave the dish uncovered.
Return the casserole to the oven and bake uncovered for an additional 10–15 minutes, or until the topping is golden and crispy and the chicken is cooked through (165°F internal temperature).
Let the casserole rest 5 minutes before serving.

Why This Recipe Belongs in Your Rotation

This casserole blends convenience and familiarity. It uses store-bought marinara so you skip a long sauce-making step, and it assembles in the dish you bake it in. That single-dish approach saves time and eliminates extra pans.

It’s also family-friendly: the flavors are classic and simple, which means picky eaters often approve. At the same time, the whole-grain pasta and skim mozzarella make it a lighter take on a much-loved comfort dish. You get that cheesy, tomato-forward satisfaction with fewer calories and the texture contrast of a crunchy topping.

Finally, it’s flexible. Swap in a different pasta shape, use a low-sodium marinara, or skip the diced tomatoes if you like things saucier or drier. The technique stays the same, and it always finishes under an hour from start to finish.

International Equivalents

Metric conversions and equivalents to help cooks outside the U.S.:

Oven: 375°F ≈ 190°C (fan ovens may use a slightly lower temperature; reduce by ~10–15°C if needed).
Dish: 9 x 13-inch casserole ≈ 23 x 33 cm.
Pasta & Chicken: 1 pound ≈ 450 g (so use 450 g penne and 450 g chicken).
Marinara: 24–25 oz jar ≈ 680–710 g.
Diced tomatoes: 15 ounces ≈ 425 g canned diced tomatoes.

What You’ll Need (Gear)

9 x 13-inch (23 x 33 cm) casserole dish — the recipe is sized for this dish; smaller dishes will overflow, larger ones may be shallow.
Large pot — for boiling the penne to al dente.
Colander — to drain the pasta.
Mixing spoon or spatula — for combining ingredients in the casserole dish.
Small bowl — for mixing the Panko, parmesan, and seasoning.
Aluminum foil or lid — to cover during the first bake so the dish steams and heats evenly.
Meat thermometer (optional but helpful) — confirms chicken reaches 165°F / 74°C.

Errors to Dodge

Skipping al dente: Overcooking the pasta before baking leads to a soggy casserole. Drain as soon as it’s al dente; it will finish cooking in the oven.
Using too much sauce: Overly wet marinara or doubling the diced tomatoes can leave the casserole soupy. If your jar is very thin, reduce the optional diced tomatoes or drain them slightly.
Not covering for the first bake: Leaving it open the whole time dries the chicken and crisp-tops the breadcrumb too early. Cover for 30 minutes, then uncover for the final crisp.
Skipping the rest time: Cutting immediately after baking makes the casserole fall apart. Let it rest 5 minutes for cleaner portions.

Health-Conscious Tweaks

This recipe already leans lighter, but here are practical adjustments you can make without rebuilding the dish:

Lower sodium: Choose a no-sugar-added, low-sodium marinara and skip extra salt in the breadcrumb mixture.
Boost veg: Stir in a cup of baby spinach or a grated zucchini (squeeze out excess moisture) when you add the mozzarella. The additional veg blends in and bulks up the fiber without changing technique.
Lean protein swap: You can use diced turkey breast instead of chicken if you prefer; keep the same weight and cook the same way.
Lower topping calories: Reduce Panko to 1/3 cup and bulk the crunch with 2 tablespoons of crushed whole-grain cereal or ground almonds if desired.

Testing Timeline

I test-baked this recipe multiple times to hit reliable timing. Expect the following timeline when you make it:

Prep (chopping/pasta): 10–15 minutes. Boiling the pasta is the longest active step.
First bake (covered): 30 minutes at 375°F / 190°C. This heats the chicken through and warms the pasta so cheese melts evenly later.
Top and finish (uncovered): 10–15 minutes to crisp and brown the topping and fully melt the mozzarella.
Rest: 5 minutes before serving. Total active hands-on time is modest; total clock time is about 55–60 minutes from start to table.

Freezer-Friendly Notes

This casserole freezes well both before and after baking.

Freeze before baking: Assemble everything in an oven-safe, foil-covered container, then freeze. When ready to cook, bake covered at 375°F / 190°C for 45–60 minutes (time will vary), then add topping and bake uncovered 10–15 minutes. Use a thermometer to ensure the chicken reaches 165°F.
Freeze after baking: Cool completely, then wrap tightly with foil and freeze up to 3 months. Reheat covered in a 350°F / 175°C oven until warmed through, then uncover to crisp the topping.
Thawing tip: If possible, thaw overnight in the fridge before reheating for more even warming and shorter oven time.

Handy Q&A

Can I use pre-cooked or rotisserie chicken? Yes. If using pre-cooked chicken, reduce initial baking time slightly since the goal is to heat everything through and melt cheese rather than cook raw chicken.

Is the diced tomato really optional? Yes. The 1 jar marinara is usually enough liquid. Add the diced tomatoes if you want extra texture and brightness, but drain slightly if your marinara is thin.

Can I make this gluten-free? Swap in a gluten-free pasta and gluten-free breadcrumbs. The method stays identical.

What if the top browns too quickly? Move the casserole to a lower rack or loosely tent with foil during the last few minutes and then remove to finish crisping.

How do I know the chicken is done? Use a meat thermometer — the internal temperature should read 165°F / 74°C. Bite-size pieces usually reach this during the covered bake time.

The Takeaway

This Skinny Chicken Parmesan Casserole is a practical, crowd-pleasing weeknight solution. It’s straightforward to assemble, trims back on fat without sacrificing texture, and scales well for families or meal prep. Keep a good jar of marinara on hand and you’ll have dinner on the table in under an hour with minimal fuss.

Make it your own with a handful of spinach or a different cheese, but trust the basic method: al dente pasta, covered bake, a cheesy stir-in, and a golden Panko-parmesan top. Simple, reliable, and delicious—exactly what a weeknight needs.

Print Recipe Save it for later

Skinny Chicken Parmesan Casserole

A lighter chicken Parmesan baked casserole with whole-grain penne, marinara, diced tomatoes, and a crispy whole-wheat Panko and Parmesan topping.

Prep Time5

Cook Time40

Total Time45

Course: Main Course

Cuisine: Italian-American

Servings: 8 servings

Ingredients

1 poundpenne pastawhole grain
1 jarmarinara sauce24-25 ounce jar no sugar added
15 ouncesdiced tomatoesoptional
1 poundboneless and skinless chicken breastscut into bite size pieces
1 cupskim mozzarella cheeseshredded
1/2 cupPanko bread crumbswhole wheat
1/4 cupgrated parmesan cheese
1 teaspoonItalian Seasoningoptional ground oregano

Instructions

Preheat the oven to 375°F. Grease a 9 x 13-inch casserole dish or spray lightly with cooking spray.
Cook 1 pound penne pasta according to the package directions until al dente. Drain and set aside.
In the prepared 9 x 13-inch casserole dish, combine the cooked pasta, 1 jar marinara sauce (24–25 oz), 1 pound boneless skinless chicken breasts cut into bite-size pieces, and 15 ounces diced tomatoes (if using). Stir until evenly combined.
Cover the casserole dish tightly with foil or a lid and bake at 375°F for 30 minutes.
While the casserole bakes, mix 1/2 cup whole wheat Panko bread crumbs, 1/4 cup grated parmesan cheese, and 1 teaspoon Italian Seasoning (if using) in a small bowl; set aside.
After 30 minutes, remove the casserole from the oven and stir in 1 cup shredded skim mozzarella cheese until evenly distributed.
Sprinkle the breadcrumb-parmesan mixture evenly over the top of the casserole. Leave the dish uncovered.
Return the casserole to the oven and bake uncovered for an additional 10–15 minutes, or until the topping is golden and crispy and the chicken is cooked through (165°F internal temperature).
Let the casserole rest 5 minutes before serving.

Equipment

9 x 13-inch casserole dish
Large Pot
Colander
Mixing Bowl
Foil
Oven

Notes

We’ve made the casserole with and without the diced tomatoes. It’s delicious either way. It really depends on how much tomato flavor you prefer.
For an even cheesier casserole, add an additional 1/4 cup Ricotta and 1/4 cup cottage cheese. Stir in along with the mozzarella.
For avegetarian dish, leave out the chicken and follow the directions as indicated.
Garnish with fresh basil, if desired.
This casserole is truly versatile. 🙂