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You ever have one of those weeks where everything in the fridge is just… staring at you?

I had one of those last Tuesday. I’d done the big grocery run on Sunday—full of ambition, full of ideas. You know how it goes. But come midweek, I was tired, dinner needed to happen, and I had exactly 20 minutes of energy left in me. What I did have? A handful of zucchini, a splash of cream, and half a block of Parmesan that needed using up.

And let me tell you—this casserole? It turned my tired, slightly cranky evening into the kind of cozy night that ends with a second helping and a quiet “dang, that was good.”

It’s humble, it’s easy, and it’s honestly a little magical. It’s the kind of recipe that doesn’t try to show off—but still ends up being the favorite at the table.

What Makes This Casserole So Stinkin’ Good?

Let me count the ways…

It’s got that buttery, cheesy top that you need in your life
The zucchini stays tender but doesn’t go all mushy on you
You get creamy comfort with hardly any fuss
It’s weeknight easy, but it wouldn’t be out of place on the holiday table
And it reheats beautifully—like, “secret midnight snack” beautifully

Ingredients — aka “What You’ll Scrounge from the Fridge”

This is a pantry-meets-garden kind of dish. Here’s what I grabbed:

Zucchini: 3–4 medium ones. If they’re on the larger side, just trim ‘em and slice thin.
Yellow onion: Gives it that sweet base flavor. You could use red onion, shallots, or even skip it if needed.
Garlic: I never measure. A spoonful or two. You get it.
Butter: Two tablespoons—one for cooking, one for mixing.
Heavy cream: Start with ½ cup. More if you want extra richness. I won’t stop you.
Egg yolk: Just the yolk. It helps it all set up just enough without feeling eggy.
Parmesan cheese: Fresh if you have it. Pre-shredded is fine. No judgment here.
Panko breadcrumbs: They make the magic crispy top.
Dried oregano & basil: Or Italian seasoning. Just a pinch of something herby.
Salt & pepper: Add it as you go—don’t be shy.
Fresh basil (for garnish): Optional, but it makes it look like you tried.

How I Threw It Together (And You Can Too)

This recipe doesn’t call for perfection—just a spoon, a bowl, and a little love.

Preheat the oven to 400°F.
Sauté your onions and garlic in 1 tbsp of butter with a pinch of salt and pepper. Let ‘em get soft and fragrant.
Mix your creamy base: In a medium bowl, stir the other tablespoon of melted butter with heavy cream and the egg yolk. Add in the onion/garlic mix.
Fold in the zucchini: Toss in the slices, sprinkle in oregano and basil, and stir in half the Parmesan. Don’t worry if it looks a little loose—it’ll tighten up in the oven.
Transfer to a greased baking dish. I like to stack the zucchini slices horizontally—it looks pretty and cooks evenly, but you can absolutely just spread them out and call it a day.
Cover with foil and bake for 10–15 minutes—just enough to get things soft and cozy.
While that’s happening, mix the panko, remaining Parmesan, and a pinch of herbs in a little bowl.
Uncover the casserole, sprinkle the breadcrumb mix generously over the top, and bake again for 15 more minutes until it’s golden and bubbling at the edges.
Let it rest for 5 minutes, then garnish with a little fresh basil if you’re feeling fancy. Or not. Either way, you’re winning.

Wanna Change It Up? Here’s How

This casserole’s not picky. You can make it your own and it’ll still love you back.

Add a handful of cherry tomatoes for a sweet pop
Use mozzarella for a stretchy, melty version
No cream? A mix of milk and sour cream will do just fine
Wanna make it a meal? Add cooked sausage, chicken, or even crumbled tofu
Keto-ish? Skip the breadcrumbs and sprinkle with almond flour or crushed pork rinds
Want spice? Add a pinch of cayenne or red pepper flakes

Leftovers? Oh, They’re Even Better

You’ll want to hide a slice for yourself.

Store in the fridge for up to 3 days
Reheat in the oven or toaster oven to keep the topping crisp
Microwave works, but the crunch will soften
I don’t freeze it—zucchini just gets weird when thawed

Let’s Keep It Real

This isn’t the kind of recipe that wins awards or goes viral. It’s not flashy. But it is the kind of recipe that you’ll make once and quietly add to your “I need something easy and delicious” rotation. It’s comfort food without the drama. It’s garden food that doesn’t feel like a salad. It’s… just good.

So if you’re staring at that zucchini in your fridge wondering what on earth to do with it—this is your answer.

And hey—if you try it, let me know! Message me, tag me, or yell at me from across the fence like a good neighbor. I wanna know what you added, how it turned out, and if your picky teenager miraculously loved it.

We’re in this zucchini thing together.

Big love from my cozy, slightly messy kitchen to yours,

Baked Parmesan Zucchini Casserole

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Prep Time 10

Cook Time 35

Course Side Dish

Cuisine American, Vegetarian

Ingredients

3-4 medium zucchini, sliced into discs
1 small yellow onion, finely chopped
2 tablespoons unsalted butter, divided
1-2 tablespoons minced garlic
1/2-1 cup heavy cream
1/2 cup grated Parmesan cheese, divided
1 large egg yolk, whisked
cooking oil spray, for baking
1/2 teaspoon dried oregano
1/2 teaspoon dried basil
1/2 cup panko breadcrumbs
Kosher salt and black pepper, to taste
Fresh basil, for garnish

Instructions

Preheat oven to 400°F.
Melt 1 tablespoon butter in a skillet over medium heat. Add onion, garlic, 1 tsp salt, and 1/4 tsp pepper. Cook until onion is translucent, about 5 minutes. Remove from heat.
In a mixing bowl, combine the remaining melted butter, heavy cream, egg yolk, and the cooked onion mixture. Stir well.
Fold in zucchini slices, oregano, basil, and 1/4 cup of the Parmesan cheese. Mix until evenly coated.
Spray a baking dish with cooking spray. Spread zucchini mixture in the dish, stacking slices horizontally. Distribute any leftover mixture evenly.
Cover dish with foil and bake for 10-15 minutes until zucchini softens.
In a small bowl, mix panko breadcrumbs with remaining Parmesan and any leftover herbs.
Remove foil from dish. Sprinkle the breadcrumb mixture evenly over the top.
Return to oven and bake for another 15 minutes, or until top is golden brown and filling is bubbling.
Remove from oven, sprinkle with salt and pepper, garnish with fresh basil, and serve immediately.

Notes

You can use yellow squash in addition to zucchini. Adjust garlic and herbs to taste.

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