Campbell's Cream of Mushroom Soup Tuna Casserole Recipe: Cheesy Cornflake Crisp-Top Masterpiece

This Campbell's cream of mushroom soup tuna casserole recipe delivers the nostalgic comfort of classic family dinners with a crispy, cheesy cornflake topping that transforms it into something special.

The secret lies in balancing the creamy soup base with tender tuna, crisp cornflakes, and just the right amount of cheddar for that perfect pull-apart texture. I've perfected this version after years of testing—no more soggy tops or bland flavors.

What makes this casserole truly stand out is the foolproof technique that ensures every layer delivers: a creamy, flavorful base that's rich but not heavy, crispy cornflakes that hold their crunch, and melted cheese that binds everything together.

The preparation takes just 30 minutes, but the baking time allows flavors to meld beautifully. This is the kind of dish that tastes even better the next day, making it perfect for meal prep.

By the time it emerges from the oven, you'll have a golden-brown masterpiece with a crispy topping that gives way to tender tuna and creamy mushroom soup beneath. The aroma alone will have everyone gathering around the table, while the first bite delivers that perfect combination of textures and flavors.

This is comfort food elevated—simple enough for weeknights but impressive enough for company.

The best part? This recipe scales perfectly for crowds, and the leftovers reheat beautifully. Serve with a simple green salad or steamed vegetables to round out the meal. Let's get started on creating this timeless classic that brings back all the warmth of childhood dinners.

Ingredients for campbell's cream of mushroom soup tuna casserole

Six pantry staples and one game-changing technique. This nostalgic casserole gets a crispy, cheesy upgrade that'll change your dinner routine forever.

The Campbell's Cream of Mushroom Soup is non-negotiable here—it's the soul of this dish. Grab the condensed version (not ready-to-serve) from any grocery store, but check the expiration date. Trader Joe's and Walmart usually have it stocked year-round, and it keeps for months in your pantry. The sharp cheddar makes all the difference—Kraft 2% is fine, but Cabot or White Cheddar take it to the next level. Pre-shredded cheese gets clumpy, so grate your own. For the cornflakes, I always buy the large family-sized box—it's cheaper and lasts forever. Crush them lightly with a rolling pin or baggie and a heavy pan. Don't overdo it, or you'll lose that crunchy magic.

No Campbell's soup? Homemade mushroom cream sauce works—sauté mushrooms, onions, and garlic, then blend with cream and a splash of chicken broth. No tuna in water? Try albacore in oil (drained) for richer flavor, or chicken breast for a lighter option. Out of cornflakes? Crushed Ritz crackers or buttery round crackers like Ritz or Saltines work in a pinch. The garlic powder and onion powder are optional but add serious depth—Penzeys or McCormick are my go-tos for quality. For extra richness, stir in 2 tbsp sour cream with the soup base, but don't skip the butter—it's what makes that crispy topping sing.

This casserole tastes even better the next day—make it ahead if you can. Assemble everything up to the cheese topping, cover with foil, and refrigerate for up to 24 hours. Bake straight from the fridge, adding 5-10 minutes to the cooking time. Leftovers? Portion into glass containers and reheat covered with foil for 2 minutes before uncovering to crisp the top. Freezes beautifully for up to 3 months—just thaw overnight in the fridge before baking. The cornflake topping stays crispy if you broil it for 2-3 minutes at the end, but watch it like a hawk or it'll burn faster than you can say 'dinner's ready!'

Step-by-step instructions for Campbell's cream of mushroom soup tuna casserole

Here's the method that delivers that perfect cheesy, crispy-topped casserole every time—no guesswork involved.

In a large bowl, combine the 1.5 cups Cornflakes with the 0.5 cup Butter and 0.5 cup Milk. Stir until the cornflakes are evenly coated and the mixture looks like wet sand. This creates the signature crispy topping that makes this casserole irresistible.

Next, add the 2 cups Sharp Cheddar Cheese, 0.5 tsp Salt, 0.25 tsp Black Pepper, 0.5 tsp Garlic Powder, 0.5 tsp Onion Powder, and 0.5 tsp Dried Parsley Flakes. Mix thoroughly until the cheese is fully incorporated and the seasonings are evenly distributed. Set this mixture aside while you prepare the filling.

In a separate bowl, open the 2 cans Campbell's Cream of Mushroom Soup and stir in the 2 tbsp All-Purpose Flour until smooth. This step thickens the soup slightly, preventing a watery casserole. Add the 2 cans Canned Tuna in Water, drained well, and mix gently to distribute the tuna evenly throughout the soup.

Transfer the tuna mixture to a 9x13-inch baking dish. The soup should coat the bottom evenly, creating a perfect base for the crispy topping. Smooth the surface with a spatula for an even finish.

Sprinkle the cornflake mixture evenly over the tuna filling, pressing down gently with the back of a spoon to ensure good contact. This step is crucial—it ensures the topping browns evenly and creates that satisfying crunch.

Bake at 375°F for 25-30 minutes, until the topping is deep golden brown and the edges are bubbling. The filling should be heated through and the cheese should be fully melted. If the topping browns too quickly, tent loosely with aluminum foil to prevent burning.

Remove the casserole from the oven and let it rest for 5-10 minutes before serving. This resting period allows the filling to set slightly, making it easier to slice and serve. The cornflake topping will remain crispy while the filling stays creamy and flavorful.

Slice into squares and serve immediately. The contrast of the crispy topping with the creamy tuna filling is what makes this dish so addictive. Garnish with extra dried parsley flakes if desired, and enjoy the perfect balance of textures and flavors.

Essential equipment for this recipe

Baking Dish Essentials

For this casserole, a 9x13-inch glass baking dish is my go-to choice—it distributes heat evenly and makes slicing easier. I prefer Pyrex or CorningWare because they handle temperature changes without cracking.

If you only have a metal pan, avoid dark-colored ones (they can overbrown the edges), and consider using a light-colored aluminum pan instead. 🌡️

Never skip greasing your dish! Use 2 tablespoons of butter or nonstick cooking spray to prevent sticking. For extra insurance, I sprinkle a thin layer of cornflakes on the bottom before adding the filling—this creates a crispy barrier that keeps the casserole from clinging to the pan.

Mixing Tools

A large mixing bowl (at least 3-quart capacity) is essential for combining the cornflake topping. I use a stainless steel bowl from OXO because it's durable and easy to clean. A wooden spoon works best for mixing the cornflakes and butter—it prevents the mixture from sticking to metal utensils.

For the filling, a medium-sized bowl (about 2-quart) is perfect for mixing the soup and tuna. Avoid plastic bowls when heating ingredients—opt for glass or stainless steel to prevent melting or warping. A rubber spatula helps scrape every last bit of filling into the baking dish.

Measuring & Prep

Precision matters with this recipe! Invest in a set of measuring cups and spoons—I recommend OXO Good Grips for their ergonomic design. For the cornflakes, a rolling pin or heavy pan works best to crush them lightly.

Place them in a ziplock bag and roll with the pin for even crushing.

A microplane is a game-changer for grating sharp cheddar cheese—it yields finer, more even shreds than a box grater. If you don’t have one, a box grater with small holes works in a pinch.

For the tuna, use a slotted spoon to drain it thoroughly before mixing into the soup.

Oven & Broiler Tips

Your oven should be preheated to 375°F for even baking. A digital oven thermometer (like Thermoworks) ensures accuracy—some ovens run 25°F hotter or cooler than set. Place the thermometer near the baking dish to monitor temperature during cooking.

For an extra-crispy topping, finish under the broiler for 2-3 minutes on high. Keep a close eye—cornflakes burn faster than you’d think! If your broiler isn’t strong, 500°F works well in a conventional oven. Use a heat-resistant spatula to check the topping’s progress.

Frequently asked questions