This keto pizza casserole is a crave-worthy, low-carb twist on loaded pizza. Roasted cauliflower replaces the crust, while Italian sausage, diced pepperoni, and a blend of melty cheeses deliver the familiar savory flavors. Ready in about 45 minutes and designed to feed a crowd, it’s ideal for busy weeknights, casual dinners, or meal prep. The cauliflower roasts until golden and slightly caramelized so it holds its texture under the sauce and cheese, and the top turns bubbly and lightly browned for that irresistible finish.
This Really Does Taste Like Pizza (I Promise)
The key to getting authentic pizza-like flavor without the crust is twofold: roast the cauliflower first, and incorporate pepperoni into the meat layer as well as using slices on top. Roasting drives off excess moisture so the casserole stays saucy rather than watery, and it develops a nutty, caramelized edge that stands up to marinara and cheese. Mixing diced pepperoni into the sausage adds rendered fat and a concentrated pizza flavor to every bite, while whole pepperoni on top crisps and curls as it bakes.
You’ll know the casserole is done when the cheese is fully melted, starting to brown slightly, and the sauce is bubbling at the edges. Let it rest a few minutes before slicing so the layers settle for clean portions.
Gluten-Free Cooking Tips
- Roast the cauliflower until golden: Lightly roasted cauliflower often releases too much liquid while baking. Roast at high heat until the edges are golden-brown, not just fork-tender.
- Use a thick marinara: A thin sauce will pool in the casserole. Choose a naturally thick marinara or strain excess liquid before using.
- Layer the cheese: Splitting cheese between layers helps the casserole hold together and ensures melty cheese in every bite, not just on the surface.
Keto Pizza Casserole
Equipment
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1 9″x13″ baking dish
Ingredients
- 1½ tbsp olive oil, divided
- 12 oz. bag cauliflower florets (about 4 cups)
- 1 small yellow onion, diced
- 1 medium green bell pepper, diced
- 1 lb ground Italian sausage
- ¾ tsp Italian seasoning
- ¾ tsp garlic powder
- ½ tsp salt
- ½ tsp black pepper
- 4 oz package pepperoni, diced (plus 12 whole slices for topping)
- 2 cups tomato marinara sauce (use a thick sauce)
- 1½ cups shredded cheese (blend of cheddar and mozzarella suggested)
- ½ cup freshly shredded Parmesan
- ¼ cup fresh basil, finely chopped
Instructions
- Preheat the oven to 425°F (218°C). Line a sheet pan with parchment and lightly oil a 9×13-inch baking dish.
- Toss cauliflower with 1 tbsp olive oil, a pinch of salt, and pepper. Spread in a single layer on the sheet pan and roast 15 minutes, until edges are golden and florets are fork-tender. Reduce oven temperature to 350°F (177°C).
- Heat remaining ½ tbsp olive oil in a large skillet over medium heat. Sauté the diced onion and bell pepper 5–8 minutes, until the onion is translucent and the pepper is softened.
- Add the ground Italian sausage, Italian seasoning, garlic powder, salt, and pepper. Cook, breaking up the meat, until no longer pink. Stir in the diced pepperoni and the marinara sauce and simmer 1–2 minutes to meld flavors.
- Place the roasted cauliflower in the prepared baking dish. Spread half of the sausage–marinara mixture evenly over the cauliflower, then sprinkle with half of the shredded cheese.
- Repeat with the remaining sausage mixture and shredded cheese. Sprinkle the Parmesan over the top and arrange 12 whole pepperoni slices evenly across the surface.
- Bake at 350°F (177°C) for 10–15 minutes, until the cheese is melted and beginning to brown and the sauce is bubbling at the edges.
- Remove from the oven, sprinkle with chopped basil, let rest a few minutes, then slice and serve.
Notes
- If your marinara is thin, strain excess liquid before adding it to the sausage to prevent pooling in the casserole.
- Frozen cauliflower should be fully thawed and patted dry before roasting, or add a few extra minutes to the roast time.
- Swap in 2 cups of another low-carb vegetable or extra cooked meat if you don’t have cauliflower on hand.
- Use hot Italian sausage and a pinch of red pepper flakes to increase heat, or mild sausage for a kid-friendly version.
- Any melty cheese blend works well; pre-shredded pizza blends are convenient if you prefer them.
- Glass, ceramic, or metal baking dishes all work—glass and ceramic retain heat longer once out of the oven.
- Store leftovers in an airtight container in the refrigerator for up to 4 days, or freeze for up to 2 months.
Nutrition
Serving: 1 | Calories: 292 kcal | Carbohydrates: 6 g | Protein: 13 g | Fat: 24 g | Sodium: 885 mg
Nutrition information is automatically calculated and should be used as an approximation.
How to Make Keto Pizza Casserole Step by Step
Gather ingredients, roast the cauliflower, sauté the vegetables, brown the sausage with seasonings, stir in diced pepperoni and marinara, and layer everything in a 9×13 baking dish with cheese between layers. Bake until bubbly and garnish with fresh basil.
Serving Suggestions
Serve this casserole straight from the dish with a crisp green salad dressed in tangy balsamic vinaigrette to cut through the richness. For a heartier spread, pair with keto zucchini fries for crunchy dipping. For a lighter option, steamed or roasted green beans complement the casserole’s soft, cheesy texture.
Storage Instructions
Refrigerate leftovers in an airtight container for up to 4 days. To freeze, cool completely and transfer to a freezer-safe container or wrap tightly; freeze for up to 2 months. Thaw overnight in the refrigerator before reheating.
Reheating
Reheat single servings in the microwave in 30-second bursts until warm. For larger portions, cover with foil and warm in a 350°F oven for 15–20 minutes. If the casserole was frozen, pat the surface lightly with a paper towel before reheating to remove excess moisture.
Make Ahead
Roast the cauliflower and prepare the sausage mixture up to 2 days in advance. Store components separately in the refrigerator, assemble when ready, and bake just before serving for best texture.
More Easy Weeknight Dinner Ideas
- Sloppy Joe Tater Tot Casserole: A layered, family-style casserole with seasoned meat and melted cheddar.
- Walking Taco Casserole: All the taco flavors layered with cheese and baked into one shareable dish.
- Keto Jalapeño Poppers: Spicy, cheesy bites that make a great appetizer alongside this casserole.
- Gluten-Free Turkey Meatballs: Simple, Italian-seasoned meatballs that freeze and reheat well.