Deep Dish Pizza Casserole

Deep Dish Pizza Casserole brings pizza-night flavor into a hearty baked dinner that is easier to serve than a true deep-dish pie. It has a thick sausage tomato sauce, plenty of mozzarella and Parmesan, classic pizza toppings, and a golden crust-style batter that bakes right over the casserole.

This is the kind of recipe that makes sense for family dinners, potlucks, game nights, or any night when everyone wants something cheesy and filling. It gives you the comfort of deep-dish pizza without shaping dough or worrying about a springform pan.

Why This Casserole Works

The casserole works because the sauce is thick, the cheese layer is generous, and the batter is sturdy enough to bake into a golden top. If the sauce is watery, the crust can turn heavy. If the batter is too thin, it will sink instead of forming a satisfying layer.

Browning the sausage first gives the tomato sauce real flavor. Simmering the sauce before assembly concentrates it, and letting the baked casserole rest helps the layers slice cleanly instead of sliding apart.

Think of this as a layered casserole inspired by deep-dish pizza, not a regular pizza baked in a dish. The crust batter behaves more like a savory cobbler topping, so it needs a thick base underneath and enough oven time to set. That is what gives each square a hearty, scoopable structure.

Ingredients

1 pound ground Italian sausage
1 large onion, diced
2 cloves garlic, minced
1 can, 28 ounces, crushed tomatoes
1 teaspoon dried oregano
1 teaspoon dried basil
1/2 teaspoon salt, plus more to taste
1/4 teaspoon black pepper
2 cups shredded mozzarella cheese
1 cup grated Parmesan cheese, divided
2 cups all-purpose flour
2 teaspoons baking powder
1/2 cup unsalted butter, melted
1 cup milk
2 large eggs
1/4 cup sliced pepperoni, optional
1/4 cup sliced black olives, optional

Ingredient and Pan Notes

A 9×13-inch baking dish gives the casserole enough room to bake evenly. If you use a smaller dish, the layers will be thicker and the center may need more time. Grease the dish well so cheesy edges release cleanly.

Italian sausage brings built-in seasoning, but mild ground beef or turkey can work if you season the sauce more generously. Toppings are flexible: pepperoni, olives, mushrooms, bell peppers, or cooked onions all fit the pizza-casserole idea.

If you add mushrooms, peppers, or fresh tomatoes, cook off extra moisture first. Raw watery toppings can thin the sauce and make the batter layer steam instead of bake. Pepperoni and olives are easier because they add flavor without releasing much liquid.

Step 1: Brown the Sausage

Italian sausage browning with diced onion and garlic in a skillet for deep dish pizza casserole — Brown the sausage with onion and garlic so the sauce has a savory base.

Heat a large skillet over medium heat and cook the Italian sausage, breaking it into small pieces. Add the onion and garlic and continue cooking until the sausage is browned and the onion is soft.

Drain excess grease if needed. A little fat adds flavor, but too much can make the casserole feel heavy and can keep the sauce from thickening properly.

Step 2: Simmer the Pizza Sauce

Thick tomato sausage pizza sauce simmering with oregano, basil, garlic, and onion in a skillet — Simmer the tomato sausage sauce until thick enough to hold up in the casserole.

Stir crushed tomatoes, oregano, basil, salt, and pepper into the sausage mixture. Simmer for about 10 minutes, stirring occasionally, until the sauce thickens and tastes seasoned.

The sauce should look spoonable, not watery. If it seems loose, simmer a few minutes longer. This step protects the crust layer and keeps the finished casserole from turning soggy.

Step 3: Mix the Crust Batter

Deep dish pizza casserole crust batter mixed with flour, baking powder, butter, milk, eggs, and salt in a bowl — Mix a thick spoonable crust batter that bakes into a golden casserole top.

In one bowl, whisk flour, baking powder, and salt. In another bowl, whisk melted butter, milk, and eggs. Combine wet and dry ingredients and stir just until a thick batter forms.

Do not overmix. The batter should be spoonable and slightly thick. A few small lumps are fine, but dry pockets of flour should be mixed in before assembly.

Step 4: Assemble the Casserole

Deep dish pizza casserole assembled in a baking dish with sausage sauce, mozzarella, Parmesan, pepperoni, black olives, and crust batter — Layer sauce, cheese, toppings, and crust batter in the baking dish before baking.

Spread the sausage sauce in the greased baking dish. Add mozzarella and part of the Parmesan, then scatter pepperoni and olives over the top if using. Spoon the crust batter over the cheese layer and spread it gently.

The batter does not need to cover every corner perfectly. As it bakes, it will puff and settle into the top layer. Leave some topping peeking through if you want more of a pizza look.

Try to keep the batter layer fairly even so it bakes at the same pace across the dish. A few thinner spots are fine, but large thick mounds may stay doughy in the center while the edges brown.

Step 5: Bake Until Golden

Fully baked deep dish pizza casserole with golden crust, melted mozzarella, pepperoni, black olives, and browned edges — Bake until the top is golden, the cheese bubbles, and the center is set.

Bake at 350°F for 30 to 40 minutes, or until the top is golden, the edges are bubbling, and the center is set. Sprinkle remaining Parmesan near the end if you want a more savory top.

If the top browns before the middle is done, tent loosely with foil and continue baking. Let the casserole rest for 10 minutes after it comes out of the oven so the layers firm up.

The center should not jiggle like loose batter when the dish is moved. If you are unsure, check the middle with a small knife. It should come out with sauce and melted cheese, not raw batter.

Slice and Serve

Served square slice of deep dish pizza casserole showing sausage sauce, melted cheese, pepperoni, olives, and golden crust layers — Let the casserole rest before slicing so the layers hold together on the plate.

Cut the casserole into squares and serve warm. A simple green salad, roasted vegetables, garlic bread, or steamed broccoli balances the rich sauce and cheese.

For a pizza-night table, set out extra Parmesan, crushed red pepper, basil, or warm marinara. The casserole is already hearty, so the best sides are usually fresh or crisp.

Make-Ahead, Storage, and Reheating

You can make the sausage sauce a day ahead and refrigerate it. Assemble the casserole shortly before baking so the crust batter stays light. If assembling ahead, keep the batter separate until baking time.

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat covered in a 350°F oven until warm, then uncover briefly to refresh the top. The microwave works for single servings, but the crust will soften.

For cleaner leftovers, chill the casserole before cutting the remaining portions. Cold squares lift out more neatly and can be reheated on a parchment-lined tray. This is useful if you want lunch portions that still look like slices rather than scoops.

Tips for Deep Dish Pizza Casserole

Simmer the sauce until thick before assembly.
Grease the baking dish well.
Use a 9×13-inch dish for even baking.
Do not overmix the crust batter.
Let the casserole rest before slicing.
Add watery toppings, such as mushrooms or peppers, only after cooking off extra moisture.

More Comfort Food Dinners

For more cozy dinner ideas, try Chicken Alfredo Baked Ziti, Creamy Bacon Cheese Dip Recipe, Baked Honey Garlic Chicken, or browse more Food & Drink recipes.

Deep Dish Pizza Casserole is best when the sauce is thick, the batter is not overworked, and the casserole gets a short rest before serving. That is what gives each square its hearty pizza-style layers.