Easy Low Carb Pizza Casserole

Let’s be honest – pizza cravings don’t care about your low-carb diet. I’ve been there, staring longingly at delivery menus while trying to stick to my health goals. But who says you have to choose between comfort food and keeping carbs in check? That’s exactly why this pizza casserole has become a regular at our dinner table. 

I LOVE how it has all those classic pizza flavors we crave – the melty cheese, the zesty sauce, the tasty toppings – without the heavy carb load of traditional crust. Plus, it’s one of those dishes that’s actually easier to make than ordering takeout. Just layer everything in a dish, pop it in the oven, and dinner’s basically done.

And if you’re feeding a family like I am, here’s a bonus: everyone can pick their favorite pizza toppings for their section of the casserole. No more arguments about pepperoni versus mushrooms – now that’s what I call a dinner win!

low carb pizza casserole

 

Why You’ll Love This Pizza Casserole

  • Keto-friendly comfort food – Using cauliflower instead of pasta and a low-carb sauce makes this perfect for anyone following a keto or low-carb diet while still getting that satisfying pizza flavor.
  • One-pan meal – Everything cooks in a single casserole dish, which means less cleanup and more time to enjoy your evening.
  • Customizable toppings – Just like a regular pizza, you can swap out the vegetables and meats to match your favorite pizza toppings or use what you have in your fridge.
  • Family-sized portions – This recipe makes enough to feed the whole family, and any leftovers taste even better the next day as the flavors continue to develop.
  • High in protein – With both Italian sausage and pepperoni, plus plenty of cheese, this dish keeps you feeling full and satisfied.
 

Options for Substitutions

This low-carb pizza casserole is pretty flexible and you can switch things up based on what you have:

  • Cauliflower florets: You can swap cauliflower with broccoli florets or even chopped zucchini. Just make sure to pat them dry after cooking to avoid excess moisture in your casserole.
  • Italian sausage: Ground beef, turkey, or chicken all work well here. If using leaner meats, add an extra tablespoon of olive oil to maintain moisture.
  • Pepperoni: Canadian bacon, turkey pepperoni, or even sliced salami can step in for regular pepperoni. You can also skip it if you prefer.
  • Mozzarella cheese: Any melting cheese works – try provolone, monterey jack, or a pizza cheese blend. Just keep the amount the same.
  • Low-carb pasta sauce: Regular marinara works if you’re not strictly low-carb. You can also use crushed tomatoes mixed with Italian seasoning and a pinch of salt.
  • Italian seasoning: Out of Italian seasoning? Mix equal parts dried basil, oregano, and thyme. Or just use what you have from these three herbs.
low carb pizza casserole
 

Watch Out for These Mistakes While Cooking

Another common mistake is using a pasta sauce that’s too thin or watery, so stick with a thick, high-quality marinara sauce (like Rao’s) and avoid budget brands that tend to be more liquid.

For the best texture and flavor, let the casserole rest for 10–15 minutes after baking to allow the cheese to set and the flavors to meld together.

And don’t forget to drain your cooked Italian sausage well to prevent excess grease from pooling in your casserole.

 

What to Serve With Pizza Casserole?

Since this pizza casserole is already packed with protein and veggies, I like to keep the sides simple and fresh.

A crisp garden salad with mixed greens, cucumber, and a light Italian dressing makes the perfect companion to balance out the richness of the casserole.

For a low-carb bread option, try some cheese-topped zucchini boats or keto garlic knots – they’re great for soaking up any extra sauce.

If you’re feeding folks who aren’t counting carbs, a basket of warm garlic bread on the side will make everyone happy!

 

Storage Instructions

Keep Fresh: This pizza casserole is perfect for leftovers! Just pop it in an airtight container and keep it in the fridge for up to 4 days. The flavors actually get EVEN BETTER as they meld together, making it a great meal prep option for busy weekdays.

Freeze: You can freeze this casserole either before or after baking. If freezing unbaked, assemble everything in a freezer-safe dish, wrap it well with foil, and freeze for up to 3 months. For baked leftovers, portion them into freezer containers and they’ll keep well for up to 2 months.

Reheat: To warm up refrigerated leftovers, pop them in the microwave for 2-3 minutes or heat in the oven at 350°F for about 15-20 minutes until heated through. If reheating from frozen, thaw overnight in the fridge first, then heat until the cheese is bubbly and everything’s nice and hot.

 

low carb pizza casserole
 

How to Know When the Pizza Casserole is Done

You’ll know your pizza casserole is ready when the cheese on top has melted completely and developed some light brown spots, typically after about 25-30 minutes in the oven.

The sauce should be bubbling around the edges, and the vegetables should be tender when pierced with a fork – especially the cauliflower florets, which you can test by inserting a knife into the largest piece.

If you’re concerned about doneness, carefully lift a corner with a spatula to check that the bottom layer isn’t too watery; the sauce should be thick and reduced, not soupy.

 

Low Carb Pizza Casserole FAQ

Why isn’t my casserole as crispy on top as I’d like?

If you want a crispier top, try broiling the casserole for the last 2-3 minutes of cooking. I always keep a close eye on it during broiling because the cheese can go from perfectly golden to burnt pretty quickly. Just make sure your baking dish is broiler-safe before trying this method.

Why is there liquid at the bottom of my casserole?

This can happen because cauliflower releases water while cooking. To prevent excess liquid, I make sure to thoroughly brown the sausage and drain any fat before adding it to the casserole.

You can also let the casserole rest for about 10 minutes after baking – this helps the liquid settle and makes serving easier.

 
Preparation Time15-20 minutes
Cooking Time30-40 minutes
Total Time45-60 minutes
Level of DifficultyMedium
 

Ingredients

  • 14 ounces cauliflower florets (bite-size)
  • 2.5 ounces pepperoni slices
  • 2 pounds italian sausage (casings removed if applicable)
  • 1 tablespoon olive oil
  • 8 ounces sliced mushrooms
  • 1 green bell pepper (bite-size)
  • 12 ounces shredded mozzarella cheese
  • 1.5 cups low-carb pasta sauce (such as rao’s marinara)
  • 1/4 cup grated parmesan cheese
  • 1 teaspoon italian seasoning
 

Step 1: Prepare and Steam the Cauliflower

  • 14 ounces cauliflower florets (bite-size)

Begin by cutting the cauliflower into florets.

Place the cut cauliflower in a microwave-safe bowl with 1 cup of water.

Cover the bowl with a damp paper towel and microwave on high for approximately 3 minutes or until the cauliflower is tender.

Be sure not to overcook.

Once done, drain the water and pat the cauliflower dry with a paper towel.

Set aside.

 

Step 2: Cook the Sausage and Mushrooms

  • 2 pounds italian sausage (casings removed if applicable)
  • 1 tablespoon olive oil
  • 8 ounces sliced mushrooms

Preheat your oven to 400 degrees F.

In a large skillet over medium-high heat, cook the Italian sausage for approximately 15 minutes until fully cooked.

Drain any excess fat and set the sausage aside.

In the same skillet, add a bit of olive oil and sauté the mushrooms over medium-high heat for 10 minutes to remove excess water.

Set the mushrooms aside once done.

 

Step 3: Prepare the Casserole Dish

  • 1 green bell pepper (bite-size)
  • 1.5 cups low-carb pasta sauce (such as rao’s marinara)

Prepare a 13×9 inch casserole dish by spraying it with non-stick spray.

Spread ½ cup of pasta sauce on the bottom of the dish to create the base layer.

In a large bowl, combine the steamed cauliflower, cooked Italian sausage, sautéed mushrooms, and green peppers.

Toss the ingredients together until well mixed.

 

Step 4: Assemble the Layers

  • 2.5 ounces pepperoni slices
  • 12 ounces shredded mozzarella cheese

Spread half of the mixed ingredients into the casserole dish.

Top this layer with ½ cup of pasta sauce, followed by half of the pepperonis (press them down slightly among the other toppings), and then 6 ounces of mozzarella cheese.

Next, spread the remaining mixture over the first cheese layer.

Top with the remaining ½ cup of pasta sauce, followed by the remaining pepperonis (reserving 10 slices for the top), and the remaining 6 ounces of mozzarella cheese.

 

Step 6: Add Final Toppings and Bake

  • 1/4 cup grated parmesan cheese
  • 1 teaspoon italian seasoning

In a small bowl, mix together the Parmesan cheese and Italian seasoning.

Sprinkle this mixture evenly over the casserole.

Arrange the reserved 10 slices of pepperoni on top.

Place the casserole in the preheated oven and bake for 30 minutes, or until the casserole is heated through and the cheese is fully melted.

 

Step 7: Serve

Once baked, carefully remove the casserole dish from the oven.

Let it cool for a few minutes before serving.

Enjoy your delicious, hearty cauliflower and sausage casserole!


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