Zucchini Pizza Casserole (Low-Carb & Gluten-Free)

A low-carb, gluten-free dinner bursting with cheesy pizza flavor, all built on a savory zucchini crust.

Every summer, my garden goes completely off the rails with zucchini. I’ve already made zucchini bread twice. Passed bags of it to neighbors. And there’s still more staring at me from the counter.

That’s when this recipe saved me.

Zucchini Pizza Casserole sounds a little unexpected. But the moment it comes out of the oven, golden, bubbling, smelling exactly like pizza night, you forget you’re eating a vegetable dish. I’ve served this to picky kids and skeptical adults. Every single time, the pan is empty.

What makes it work? The crust. Shredded zucchini mixed with eggs and three cheeses bakes into a firm, sliceable base. It holds up beautifully under a hearty meat sauce. No flour, no bread, no dough. Just honest ingredients doing a really good job.

This is weeknight dinner that feels indulgent but keeps things light. Naturally low-carb. Naturally gluten-free. But honestly, I make it because it tastes fantastic.

Detail	Value
Prep Time	10 minutes
Cook Time	40 minutes
Total Time	50 minutes
Servings	8
Difficulty	Easy

Ingredients

Ingredient	Quantity	Notes
Zucchini, unpeeled and shredded	4 cups	No need to peel; use a box grater or food processor
Salt	1/2 tsp	Draws out moisture from the zucchini
Large eggs	2	Binds the zucchini crust together
Parmesan cheese, grated	1/2 cup	Adds sharp, nutty flavor to the crust
Mozzarella cheese, shredded	2 cups	Divided, half in crust, half on top
Cheddar cheese, shredded	1 cup	Divided, half in crust, half on top
Ground beef	1 lb	Use 90% lean for best results
White onion, chopped	1/2 cup	Yellow onion also works
Garlic, minced	2 cloves	Fresh preferred for bold flavor
Tomato sauce or marinara	1 (15 oz) can	Italian-style sauce adds extra herb flavor

Pro Tip: Freshly grating your own mozzarella and cheddar makes a noticeable difference. Pre-shredded bags contain anti-caking agents that can mess with how the cheese melts.

How to Make It

Once you run through this a couple of times, it becomes second nature. Two clear stages: build and bake the crust, then add sauce, top with cheese, and finish in the oven.

Step 1: Draw Out the Moisture

Place your shredded zucchini in a colander set over the sink. Sprinkle the salt evenly over it. Give it a gentle toss. Let it sit for 10 minutes.

The salt pulls water out of the zucchini. You’ll see quite a bit collect at the bottom. After 10 minutes, transfer the zucchini to a clean kitchen towel or several layers of paper towels. Wrap it up and squeeze firmly. Keep squeezing until no more liquid comes out.

This step is non-negotiable. Wet zucchini means a soggy crust. Full stop.

Pro Tip: Don’t rush this. A thorough squeeze is the single biggest factor in whether your crust holds together or turns into a watery mess. Two rounds of squeezing is not too much.

Step 2: Build the Zucchini Crust

Preheat your oven to 400°F. Grease a 13×9-inch baking dish well with nonstick cooking spray.

Add the drained zucchini to a large mixing bowl. Crack in the two eggs and stir to combine. Add the Parmesan, then half the mozzarella and half the cheddar. Mix until everything is evenly distributed.

Transfer the mixture into the prepared dish. Press it out into an even layer. Use the back of a spoon or damp hands to smooth it right to the edges and corners. A uniform thickness means it bakes evenly.

Slide it into the oven and bake for 20 minutes. The crust should look set and lightly golden at the edges when it comes out.

Step 3: Cook the Meat Sauce

While the crust bakes, get your sauce going. Place a large skillet or saucepan over medium heat. Add the ground beef and chopped white onion together.

Cook, breaking the beef apart as you go, until no pink remains. About 8 to 10 minutes.

Drain the excess fat from the pan. Add the minced garlic and cook for one minute, stirring constantly so it doesn’t scorch. Pour in the tomato sauce or marinara. Stir everything together. Let it simmer for 2 to 3 minutes until slightly thickened.

Pro Tip: Use a marinara you genuinely love. It drives the whole dish. Italian-style tomato sauce with herbs already blended in works especially well here.

Step 4: Assemble and Finish

Pull the baked zucchini crust out of the oven. Spoon the meat sauce evenly over the top, spreading it all the way to the edges.

Scatter the remaining mozzarella and cheddar over the sauce. These cheeses will melt into a golden, bubbling layer that looks just like pizza out of a proper oven.

Return the dish to the oven. Bake for another 20 minutes, until the cheese is fully melted and the casserole is piping hot throughout.

Step 5: Rest and Serve

Remove the casserole from the oven. Let it rest for 5 minutes before slicing. This short rest lets it firm up just enough to cut clean squares.

Slice into 8 portions and serve directly from the dish. It goes great with a simple green salad or some garlic bread on the side.

Make It Your Own

One of the best things about this casserole? How flexible it is. Once you have the base recipe down, you can swap and customize almost everything on top.

Protein swaps:

• Italian sausage, mild or hot, adds a lovely herby depth
• Ground turkey keeps it lighter while still being filling
• Skip the meat entirely and load up with vegetables for a fully vegetarian version

Cheese variations:

• Provolone, Asiago, or smoked mozzarella all work beautifully
• Want a sharper finish? A sprinkle of Romano right before serving adds a nice punch

Extra toppings:

• Sliced black olives, diced bell peppers, mushrooms, or thin jalapeño slices all work great
• Layer them on top of the sauce before adding the final cheese

Sauce options:

• Pizza sauce gives a slightly sweeter, more concentrated tomato flavor
• Marinara works just as well
• Use whichever you prefer or have on hand

Storage and Reheating

Store leftovers in an airtight container in the refrigerator. They keep well for up to 4 days. Honestly, they taste even better the next day once the flavors have had time to settle.

Reheating? The oven or an air fryer works best. It crisps the crust back up instead of turning it soft. A microwave works in a pinch, though the crust will be softer.

This casserole also freezes really well. Here’s how to do it right:

• Bake it fully, then let it cool completely before freezing
• Cover it tightly and freeze
• Thaw overnight in the fridge
• Bring to room temperature before reheating uncovered at 350°F until warmed through

Frequently Asked Questions

Can I use yellow squash instead of zucchini?

Absolutely. Yellow crookneck squash has a very similar texture and moisture content. The crust will look a little different in color but behaves the same way. You can even do a 50/50 mix of both for variety.

Why did my crust turn out watery?

Almost always, the zucchini wasn’t squeezed dry enough. Zucchini holds a surprising amount of water. After salting, squeeze it as firmly as you can in a towel. Don’t rush this step. A second pass with fresh paper towels helps if the first squeeze left it still damp.

Can I make this ahead of time?

Yes, and it works really well. Bake the crust earlier in the day and let it cool. When you’re ready for dinner, add the sauce, top with cheese, and do the final 20-minute bake. The crust holds up fine for several hours at room temperature.

Do I need to peel the zucchini before shredding?

No peeling needed. The skin is thin and soft. It blends right into the crust without any chewy or tough texture. Leaving it on also keeps things simple and adds a little extra color.

What’s the best way to shred the zucchini?

A standard box grater using the large-hole side gives you nicely shredded zucchini with good texture. A food processor with the shredding disc is faster for larger batches, but produces finer shreds. If you use a processor, squeeze even more moisture out, since finer shreds release water more readily.

This Zucchini Pizza Casserole has earned a permanent spot in my regular dinner rotation. It covers every base. Fast enough for a weeknight. Satisfying enough for a crowd. Genuinely delicious from the first bite. If your garden is currently winning the zucchini battle, this is exactly the recipe you need.