Keto Pizza Casserole
Published
This keto pizza casserole is loaded with roasted cauliflower, savory Italian sausage, two kinds of melty cheese, and crispy pepperoni, giving you all the flavor of a loaded pizza with none of the crust. It comes together in about 45 minutes and feeds a crowd, which makes it perfect for busy weeknights or a laid-back Sunday dinner. The cauliflower roasts until golden and tender, soaking up all that garlicky, herby flavor, while the cheese on top gets bubbly and just barely browned. One bite and you’ll forget there’s no crust at all.
This Really Does Taste Like Pizza (I Promise)
I tested this recipe more times than I can count before I landed on the method below, and the biggest lesson I learned is that roasting the cauliflower first is non-negotiable. I get why it’s tempting to skip, it feels like one more dish to wash. But if you toss raw cauliflower straight into the casserole, it releases water as it bakes and turns the whole dish watery instead of saucy. Roasting it at high heat first drives off that extra moisture and gives the cauliflower a slightly caramelized, nutty flavor that holds up under the sauce and cheese instead of disappearing into it. It’s the same trick I rely on in my Crustless Pizza, where every ingredient has to earn its place once you take the crust out of the equation.
The other detail I found makes a real difference is mixing diced pepperoni right into the sausage layer instead of only using it as a topping. I tried it both ways while testing, and mixing it in won every single time. It renders a little of its fat into the meat mixture as everything cooks together, which is where a lot of that classic pizza flavor comes from. Whole pepperoni on top gives you the crispy, slightly curled edges you want to see, while the diced pepperoni underneath flavors every single bite.
You’ll know your casserole is ready when the cheese on top is fully melted, starting to turn golden in spots, and the sauce is bubbling gently at the edges of the dish.
Gluten-Free Cooking Tips
- Roast the cauliflower until it’s truly golden, not just tender. I tested this recipe with cauliflower that was only lightly roasted, and the casserole ended up watery on the bottom. Give it the full 15 minutes at 425°F. You’re looking for light golden-brown edges, not just fork-tender florets.
- Use a thick marinara sauce. This is the one ingredient that can make or break the texture of your casserole. A thin, watery marinara will pool at the bottom of the dish no matter how well you roast the cauliflower. I use Rao’s because it’s naturally thick and doesn’t need any doctoring. If your sauce is thinner, strain out some of the liquid before adding it to the sausage mixture.
- Layer the cheese, don’t just top it. Splitting the cheese between two layers instead of piling it all on top helps the casserole hold together when you slice it, and you get melty cheese in every bite instead of just on top.
Keto Pizza Casserole
Equipment
- 1 9"x13" baking dish
Ingredients
- 1½ tbsp olive oil, divided
- 12 oz. bag of cauliflower florets, or 4 cups
- 1 small yellow onion
- 1 medium green bell pepper
- 1 lb. ground Italian sausage
- ¾ tsp Italian seasoning
- ¾ tsp garlic powder
- ½ tsp salt
- ½ tsp black pepper
- 4 oz. package of pepperoni, uncured and GF, diced + 12 whole pepperoni for topping
- 2 cups tomato marinara sauce, I used Rao’s
- 1½ cups cheese, shredded – I used cheddar and mozzerella
- ½ cup Parmesan cheese, freshly shredded
- ¼ basil, finely chopped
Instructions
- Preheat the oven to 425°F (218°C) and line a sheet pan with parchment paper. Spray a 9×13 inch with nonstick cooking spray.
- Toss the cauliflower florets with 1 tbsp olive oil and a pinch of salt and pepper. Spread the cauliflower onto the prepared sheet pan and roast for 15 minutes. Then reduce the oven temp to 350°F (177°C).
- In a large skillet over medium heat, pour in the remaining ½ tbsp olive oil. Add the onion and green bell pepper and sauté until softened and the onions start to become translucent, about 5-8 minutes.
- Add in the ground beef, Italian seasoning, garlic powder, salt, and pepper, and cook until no longer pink. Add in the diced pepperoni and marinara and sauté 1-2 minutes more.
- Place the roasted cauliflower into the baking dish. Spread half of the sausage/marinara mix evenly on top. Top with half of the cheese.
- Repeat with an additional layer of sausage/marinara mixture and cheese.
- Top the casserole with 12 pepperonis.
- Bake at 350°F (177°C) for 10-15 minutes until the cheese has melted. Sprinkle with chopped basil.
Notes
- Thinner marinaras release more liquid as they bake, so strain out any excess liquid first, or use a thick sauce like Rao’s, which also tends to be lower in added sugar. Check the label if you’re watching sodium or sugar closely.
- Roast the cauliflower until golden, not just tender, or the casserole turns watery. Using frozen cauliflower? Thaw and pat it dry first, or add a few extra minutes to the roast time.
- No cauliflower on hand? Swap in 2 cups of any low-carb veggie or extra cooked meat.
- Use hot Italian sausage and red pepper flakes to turn up the heat, or mild sausage to keep things kid-friendly.
- Any melty cheese blend works, including a pre-shredded Italian or pizza mix.
- Glass, ceramic, or metal all work for the 13×9-inch dish, though glass and ceramic hold heat a little longer once out of the oven.
- Store leftovers in the fridge for up to 4 days, or freeze for up to 2 months.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
How to Make Keto Pizza Casserole Step by Step
Gather all the ingredients together.
Roast the cauliflower: Preheat your oven to 425°F (218°C) and line a sheet pan with parchment paper. Toss the 12 oz. bag (about 4 cups/430g) of cauliflower florets with 1 tablespoon olive oil and a pinch of salt and pepper. Spread them in a single layer on the sheet pan and roast for 15 minutes, until the edges are golden brown and the cauliflower is fork-tender. Once it’s done, reduce the oven temperature to 350°F (177°C).
Sauté the vegetables: While the cauliflower roasts, heat the remaining ½ tablespoon olive oil in a large skillet over medium heat. Add the diced small yellow onion and diced medium green bell pepper and sauté for 5 to 8 minutes, until the onion turns translucent and the pepper has softened.
Cook the sausage: Add 1 lb ground Italian sausage(454 g), ¾ teaspoon Italian seasoning, ¾ teaspoon garlic powder, ½ teaspoon salt, and ½ teaspoon black pepper to the skillet. Cook until the sausage is no longer pink, breaking it up as it browns. Stir in the diced pepperoni (from your 4 oz. package/114 g) and 2 cups (480 ml) marinara sauce, and let everything simmer together for 1 to 2 minutes so the flavors meld.
Assemble the first layer: Spray a 13×9-inch baking dish with nonstick cooking spray. Spread the roasted cauliflower evenly across the bottom. Top with half of the sausage-marinara mixture, spreading it out so every piece of cauliflower gets covered. Sprinkle with ¾ cup shredded cheese (85g).
Add the second layer: Repeat with the remaining sausage mixture, followed by the rest of the shredded cheese. Finish by arranging the 12 whole pepperoni slices on top, along with ½ cup Parmesan cheese (45g).
Bake: Bake at 350°F (177°C) for 10 to 15 minutes, until the cheese is fully melted and just starting to turn golden at the edges, and the sauce is bubbling around the sides of the dish.
Garnish and serve: Sprinkle with the ¼ cup chopped basil before serving. Enjoy!
Serving Suggestions
I love serving this casserole straight out of the dish with a simple green salad tossed in Balsamic vinaigrette salad dressing to balance out all that rich, cheesy flavor. It’s the classic way I make pizza night at home, and the tangy dressing cuts right through the richness of the casserole.
If you’re feeding a crowd and want something a little more filling, Keto zucchini fries are a great pick. They’re crispy, coated in Parmesan and almond flour, and just as good for scooping up extra sauce as a slice of bread would be, without the carbs.
For a lighter pairing, roasted or steamed green beans work well too. Their slight crunch is a nice contrast to the soft, cheesy casserole, and they come together in the same amount of time it takes the casserole to bake.
Storage Instructions
Store leftovers in an airtight container in the fridge for up to 4 days.
Freezer
Let the casserole cool completely, then transfer it to a freezer-safe container or wrap it tightly in foil. It will keep well in the freezer for up to 2 months. Thaw overnight in the refrigerator before reheating.
Reheating
Reheat individual portions in the microwave in 30-second intervals until warmed through. For a batch, cover with foil and warm in a 350°F oven for about 15 to 20 minutes. The cheese may release a little extra moisture after freezing, so a quick pat with a paper towel before reheating helps keep the texture right.
Make Ahead
You can roast the cauliflower and cook the sausage mixture up to 2 days ahead. Store them separately in the fridge, then assemble and bake when you’re ready to serve.
More Easy Weeknight Dinner Recipes to Try
- Sloppy Joe Tater Tot Casserole: Another layered, crowd-feeding casserole built on seasoned ground meat and melted cheddar, perfect if you’re looking for more easy weeknight dinners in this same style.
- Walking Taco Casserole: A different take on the same idea: layers of seasoned meat, cheese, and toppings baked into one easy, shareable dish.
- Keto Jalapeño Poppers: If you like a little heat, these are a great keto-friendly appetizer to serve alongside this casserole for pizza night or game day.
- Gluten-Free Turkey Meatballs: Another simple, Italian-seasoned, ground-meat recipe that freezes well, just like this casserole.
