Baked Tomato Soup Casserole

A cozy, crowd-pleasing baked tomato soup casserole topped with bubbly melted cheese and crispy, golden toasted bread.

Why This Recipe Works:

• Stale bread acts as a natural thickener, absorbing the rich tomato broth without collapsing into mush.
• Baking concentrates the natural sugars in the tomatoes through gentle caramelization, cutting the harsh acidity.
• A blend of low-moisture mozzarella and sharp parmesan creates the ultimate cheese pull while adding a savory, salty depth.

The first time I tried baking tomato soup was during a brutal Chicago blizzard when my radiator died and my fingers were turning blue. I desperately needed something warmer than a standard bowl of soup, so I threw everything into a baking dish.

It was a total revelation.

The oven transformed the watery tomatoes into a rich, jammy concentrate that clung to the spoon.

My first attempt was a disaster because I used cheap sandwich bread that disintegrated into mush. I didn't realize how much the moisture from the fresh tomatoes would water down the base. After testing this with six different types of bread, I finally nailed the physics of the perfect bake.

The secret lies in using stale, crusty sourdough and a touch of heavy cream to stabilize the acid. This creates a velvety, luxurious texture that holds up beautifully under a heavy blanket of melted mozzarella.

Trust me on this one.

You can also try our [baked tomato soup and grilled cheese casserole](/2026/07/grielled-cheese-easy-6557.html) for a similar cozy vibe.

This has all the comforting, bubbling warmth of a classic [macaroni and cheese](/2026/07/spicy-nashville-style-mozzarella-sticks-recipe-4191.html) but with a bright, acidic tomato punch. It is the ultimate cold-weather comfort food that comes together in a single pan.

Let's get cooking.

Baked Tomato Soup Casserole

• Publisher Storied Skillet
• Cuisine American
• Category Dinner, Casseroles
• Prep Time 15 minutes
• Cook Time 30 minutes
• Servings 4
• Calories 380 calories
• Rating 4.8 2577
• Tags tomato soup casserole, baked tomato soup, melted cheese bread topping, cozy dinner, comfort food

Ingredients

• 2 tbsp unsalted butter
• 1 medium yellow onion, finely diced
• 3 cloves garlic, minced
• 1 can (28 oz) crushed San Marzano tomatoes
• 1 cup low-sodium vegetable broth
• 1/2 cup heavy cream
• 1 tsp Diamond Crystal kosher salt
• 1/4 tsp freshly cracked black pepper
• 3 cups stale sourdough bread, cut into 1-inch cubes
• 1.5 cups shredded low-moisture mozzarella cheese
• 1/2 cup grated Parmesan cheese
• 2 tbsp extra virgin olive oil
• Fresh basil leaves, torn, for garnish

Directions

1. Preheat your oven to 375°F (190°C).
2. Melt the butter in a large oven-safe skillet or Dutch oven over medium heat. Add the diced onion and cook until soft and translucent, about 5 minutes.
3. Stir in the minced garlic and cook for 1 minute until fragrant, being careful not to burn it.
4. Pour in the crushed San Marzano tomatoes and vegetable broth. Bring to a simmer and let cook for 10 minutes to allow the flavors to meld.
5. Remove from heat and stir in the heavy cream, kosher salt, and black pepper. If you prefer a completely smooth soup, use an immersion blender to puree the mixture directly in the pot.
6. Gently fold in half of the stale sourdough cubes so they begin to absorb the soup.
7. Top the entire skillet with the remaining bread cubes, then scatter the shredded mozzarella and grated Parmesan evenly over the top.
8. Drizzle the bread cubes with the extra virgin olive oil to help them crisp up.
9. Transfer the skillet to the oven and bake for 20 to 25 minutes, or until the soup is bubbling at the edges and the cheese is melted and golden brown. Garnish with fresh basil before serving.

Notes

• Salt Conversion: This recipe specifies Diamond Crystal kosher salt. If you are using fine table salt, cut the measurement in half to 1/2 teaspoon to avoid over-salting.
• The Science of Cream: Heavy cream prevents curdling because its high fat content coats the proteins, preventing them from bonding and clumping when exposed to tomato acid.
• Workflow Warning: Watch your garlic closely when sautéing. Burnt garlic will ruin the entire tomato base with a bitter taste that cannot be masked.
• Storage Behavior: The bread topping will inevitably lose its crunch in the fridge, but reheating it in the oven restores the texture beautifully.

Serving Suggestions

Complete this cozy meal by pairing it with fresh, vibrant sides that cut through the rich, cheesy goodness of the casserole.

• A crisp green salad tossed in a light lemon vinaigrette.
• Roasted asparagus spears with a squeeze of fresh lemon juice.
• A side of crispy roasted zucchini to add some green to your plate.
• Extra slices of toasted bread for dipping into the rich soup base.

Storage and Reheating

Store any leftovers in an airtight container in the refrigerator for up to three days. The bread topping will inevitably soften as it sits in the liquid, absorbing more of the rich tomato base.

Do not microwave this.

Microwaving will turn the cheese rubbery and make the bread incredibly soggy. Instead, transfer the leftovers back into an oven-safe dish.

Reheat in a 350°F oven for about 15 minutes until the soup is hot and bubbling. This dry heat helps recrisp the bread edges and beautifully remelts the cheese blanket.

Ingredient Substitutes

If you don't have everything on hand, these simple swaps will keep your dinner on track without sacrificing flavor.

1. Sourdough Bread: You can swap this for French bread, ciabatta, or even cubed [homemade garlic bread](/2026/07/chicken-souvlaki-marinade-easy-9116.html) for an extra punch of flavor.
2. Heavy Cream: Whole milk or canned coconut milk can work, though the final texture won't be quite as velvety.
3. Mozzarella: Provolone or gruyère make excellent melting alternatives if you want a sharper flavor profile.
4. Crushed Tomatoes: If you prefer a traditional stovetop soup, try our [creamy tomato soup served in a bowl with fresh basil, black pepper, and a drizzle of cream on top.](/2026/07/bang-bang-chiken-sliders-easy-8980.html)

This dish is the ultimate warm hug on a cold night, bringing all the nostalgic joy of childhood lunches into a grown-up, single-pan masterpiece. Grab a spoon, gather your favorite people, and dig in while the cheese is still gloriously stretchy.