Pizza Spaghetti Casserole

Comfort food that tastes like pizza but comes together with the ease of a classic baked pasta—this Pizza Spaghetti Casserole is one of those weeknight winners that quickly earns a permanent place in the rotation. Think cheesy, saucy spaghetti strands studded with savory slices of pepperoni, baked until bubbly and golden on top. It’s a family-friendly meal, perfect for busy evenings, potlucks, or anytime you want pizza vibes without dealing with dough.

This version uses pantry-friendly ingredients and straightforward steps so you can have dinner on the table without fuss. The proportions are simple: a full package of spaghetti noodles, one and a half jars of spaghetti sauce, two cups of mozzarella, and a package of pepperoni. Together they form a casserole that’s both familiar and fun—comforting, sticky, and cheesy in all the right ways.

Why you’ll love this recipe

First, it’s comforting. The flavors you love from pizza—tomato sauce, melted mozzarella, and pepperoni—are all here, but mixed with spaghetti for a handheld-friendly, fork-and-plate kind of comfort. Second, it’s easy. There’s no dough to knead, no pizza stone to preheat, and no specialty equipment required. Third, it’s customizable—swap a few ingredients, add veggies, or stir in herbs to suit your family’s tastes.

Ingredients

• 1 package spaghetti noodles (17.6 oz package)
• 1.5 jars spaghetti sauce (24 oz jars)
• 2 cups Horizon Organic mozzarella cheese
• 1 package pepperoni

Prep notes and substitutions

Start by reading the ingredient list and making sure everything is measured and ready to go. If you’d like more texture, toss in a cup of chopped bell pepper or some sliced mushrooms—those work especially well with the pizza theme. If you’d prefer a slightly creamier casserole, stir in a few tablespoons of cream cheese or ricotta before transferring to the baking dish. For a keto-friendly version, use spiralized zucchini instead of spaghetti; timings and water content will change, so watch the bake closely.

For cheese, the recipe calls for two cups of mozzarella. If you like a sharper flavor, mix in a half cup of grated Parmesan or a milder provolone for extra melt. If you don’t eat pork, use beef- or turkey-based pepperoni or a vegetable-based pepperoni alternative—this keeps the dish entirely in line with the flavor profile while matching different dietary preferences.

Equipment

• Large pot for boiling pasta
• Colander
• Mixing bowl or large pot to combine sauce and pasta
• 9×13-inch or similar baking dish
• Oven preheated to 350°F (177°C)
• Cheese grater (if shredding your mozzarella)

Step-by-step instructions

1. Preheat your oven to 350°F (177°C). Lightly grease a 9×13-inch baking dish so the casserole won’t stick and will be easy to serve. This gentle temperature helps the casserole heat through without drying out.
2. Bring a large pot of salted water to a rolling boil. When the water is boiling, add the entire package of spaghetti noodles (17.6 oz package). Cook the spaghetti until it reaches al dente—firm to the bite but cooked through—following the package’s recommended time as a guideline. Stir occasionally so the noodles separate and cook evenly.
3. While the spaghetti cooks, open 1.5 jars of spaghetti sauce (24 oz jars). Pour the sauce into a large mixing bowl or a separate pot. If you prefer a saucier casserole, you can reserve a few tablespoons of sauce for topping later. For extra flavor, stir in a teaspoon of dried oregano or a pinch of red pepper flakes, but this is optional.
4. When the spaghetti is al dente, drain the noodles in a colander. Give them a quick shake to remove excess water, but avoid rinsing; the residual starch helps the sauce cling to the pasta.
5. Transfer the drained spaghetti to the bowl with the spaghetti sauce. Use tongs or a large spoon to toss the noodles and sauce together until the strands are evenly coated. Make sure the sauce is distributed through the pasta so every bite has flavor.
6. Add one package of pepperoni to the sauced spaghetti. If the pepperoni slices are whole and you prefer smaller pieces, tear or roughly chop them before adding. Mix the pepperoni into the spaghetti so it’s dispersed throughout the casserole rather than clumped in one spot.
7. Stir in 2 cups of Horizon Organic mozzarella cheese into the sauced spaghetti. Reserve a small handful of the cheese for sprinkling on top if you like a cheesy golden crust. Toss gently to combine so the cheese melts into the warm pasta but some strands still hold structure.
8. Pour the spaghetti, sauce, pepperoni, and cheese mixture into the prepared 9×13-inch baking dish. Use a spatula to spread it into an even layer. If you saved some sauce or cheese for topping, spoon it over the surface now to create a bubbly, golden top.
9. Place the baking dish in the preheated oven and bake at 350°F (177°C) for about 20 to 25 minutes, or until the cheese on top is melted and beginning to brown. The timing depends on your oven and how hot the casserole was when it went into the oven. You’re looking for bubbling sauce around the edges and a pleasing golden color on the cheese.
10. Remove the casserole from the oven and let it rest for 5 to 10 minutes before serving. This rest time helps the casserole set so portions hold together when scooped. Garnish with chopped fresh basil or a sprinkle of dried oregano if you like, then cut into squares or scoop portions onto plates and serve hot.

Serving suggestions

This casserole pairs well with a simple green salad dressed in lemon vinaigrette to cut through the richness, or stick with the pizza theme and serve alongside garlic knots or toasted baguette slices. For a family-style meal, place the casserole in the middle of the table with a few sides—crumbled salad, a jar of pickled peppers, or a bowl of marinated olives—and let everyone help themselves.

Make-ahead and storage

You can assemble this casserole a few hours in advance and keep it covered in the refrigerator until you’re ready to bake. If you want to make it a day ahead, assemble and bake it, then cool completely and cover tightly before refrigerating. Reheat in a 350°F (177°C) oven for 15–20 minutes, or until warmed through. Leftovers will keep in the fridge for up to 3 days. For longer storage, portion into airtight containers and freeze for up to 2 months. Reheat from frozen in a 350°F oven, covered with foil, until hot in the center.

Tips for success

• Don’t overcook the spaghetti. Since the casserole goes back into the oven, slightly undercooked noodles will finish cooking in the bake and retain a pleasant texture.
• Reserve some cheese for the top. A few extra handfuls of mozzarella melted on top create an irresistible golden crust.
• Even distribution matters. When mixing sauce, cheese, and pepperoni with the pasta, make sure everything is evenly dispersed so each portion tastes balanced.
• Watch the bake. If the top is browning too quickly, cover loosely with foil to prevent burning while the inside continues to heat.

Flavor variations

Want to tweak the flavor? Stir in sautéed onions and garlic for an aromatic lift, or fold in baby spinach near the end of mixing for extra color and nutrients—the heat from the pasta will wilt it perfectly. Swap out the pepperoni for sliced chicken sausage or a plant-based deli-style pepperoni to fit different preferences. Add red pepper flakes for heat, a pinch of sugar if your sauce is too acidic, or a splash of balsamic vinegar for depth.

Common questions

Can I use a different pasta? Yes. Penne, rigatoni, or any tubular pasta will work and hold sauce well. Adjust cook times as indicated on the pasta package, and follow the same general assembly steps.

Do I need to pre-mix the cheese into the pasta? You can mix some into the pasta for melty bites and reserve some for topping. Either approach works; mixing the cheese in ensures every forkful has gooey cheese throughout.

Can I double the recipe? Absolutely. Use two baking dishes and increase the oven time slightly if you’re using a deeper dish. Bake until the center is hot and the top is bubbly.

Final thoughts

This Pizza Spaghetti Casserole is the kind of dish that feels deliberately indulgent while being utterly uncomplicated to prepare. It offers the nostalgic flavors of pizza with the satisfying texture of baked pasta, and it’s adaptable enough to handle swaps and upgrades without losing its soul. Whether you’re feeding a crowd or cooking for a cozy night in, this casserole is a dependable, delicious choice that will disappear fast—every bite cheesy, saucy, and perfectly comforting.