Zucchini Casserole
Updated Jun 28, 2025
This Zucchini Casserole is made with sliced zucchini, a creamy sauce, and a golden, cheesy breadcrumb topping. The prep time is an easy 10 minutes!
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This easy zucchini casserole recipe will actually get your family excited about zucchini, it did for my family, at least! I love that it’s easy enough to prepare on a weeknight but also looks beautiful for a dinner party. So, whether you’ve got an abundance of garden zucchini to use up or you just love this fantastic vegetable, this baked zucchini casserole is a recipe that you’ll want to add to your rotation!
Happy Cooking!
– Yumna
Zucchini Casserole Ingredients
- Zucchini: Go for medium-sized zucchini. Organic if possible!
- Olive Oil: I prefer the taste of olive oil, but any cooking oil will do.
- Italian Seasoning: I like to make my own Italian seasoning, but you can use store-bought as well.
- Salt and Pepper: The classics!
- Butter: Unsalted is best, but salted is totally fine.
- Flour: I use all-purpose flour but feel free to swap in gluten-free flour as well.
- Milk: Whole milk will give you the creamiest results but low-fat milks are fine, too.
- Garlic Clove: I love fresh garlic, but you can use ½ teaspoon of powdered garlic per clove.
- Lemon Zest: You’ll just need one ripe lemon (any type will work).
- Parmesan Cheese: I love the parmesan crust on this zucchini casserole but you can also try sharp cheddar or mozzarella!
- Breadcrumbs: Classic breadcrumbs are my go-to but panko or gluten-free will work, too.
How to Make Zucchini Casserole
Make the Cream Sauce for the Casserole
Assemble and Bake
Zucchini Casserole Recipe
Ingredients
- 4 medium zucchini ends trimmed, sliced into ¼-inch thick slices
- 2 tablespoons olive oil divided, plus more for the pan
- 1 teaspoon Italian seasoning
- ½ teaspoon salt plus more to taste
- ½ teaspoon pepper plus more to taste
- 2 tablespoons butter
- 2 tablespoons flour
- 1 ½ cups milk
- 1 garlic clove grated
- 1 lemon zested
- ½ cup grated parmesan cheese
- ¼ cup breadcrumbs
Instructions
- Preheat the oven to 350˚F. Lightly coat a 9 by 13-inch casserole dish with olive oil. Add zucchini to the baking dish, then add 1 tablespoon of olive oil and toss to coat. Season the zucchini with Italian seasoning, ¼ teaspoon salt and ¼ teaspoon pepper. Toss to evenly distribute the spices and set aside.
- In a medium saucepan, add butter and set over medium-low heat. Once the butter has melted, add the flour and stir constantly until the mixture turns lightly golden brown and smells slightly nutty. Whisk in the milk, garlic and lemon zest and cook, stirring almost constantly, until the mixture has thickened and can coat the back of a spoon, about 5 to 7 minutes. Remove from heat and season to taste with salt and pepper.
- Pour the cream sauce over the zucchini. Mix the remaining olive oil with the parmesan cheese and breadcrumbs, and sprinkle on top of the zucchini.
- Bake for 40 to 45 minutes, or until the zucchini is tender (but not mushy), the sauce is bubbling, and the breadcrumbs are golden brown.
Equipment
Nutrition
Nutrition information provided is an estimate. It will vary based on cooking method and specific ingredients used.
Recipe Tips
- Try not to overcook your zucchini. Start checking the casserole around 40 minutes to make sure it’s not getting too mushy, as all ovens are different.
- Be patient when making the bechamel. You’ll want to stir it constantly to prevent the bottom from burning until your sauce starts to thicken up and coat the back of your spoon. If you place a spoon in the sauce, then draw a vertical line with your finger, the sauce should stay put, and the line should not fill back in. That’s how you know it’s ready! It takes time, but it’s worth it.
- Cut your zucchini into even slices. For uniform cooking, ensure your zucchini slices are all the same thickness. A mandoline slicer can help, but be careful when using this tool as it’s very sharp!
- Let your casserole rest. Once baked, let your casserole rest for a few minutes before serving to allow the sauce to thicken up a bit more.
Serving Ideas
- Serve with salmon. I think this rich zucchini casserole is a perfect side veggie for a cut of fresh salmon! My go-to recipe is a tasty Lemon Pepper Salmon that plays nicely off the citrus in the dish.
- Make some garlic bread. The cheesy saucy bits of this casserole are too good to let rest in the bottom of the dish! I like to mop them up with some warm homemade garlic bread.
- Add steak! Zucchini, butter sauce, and steak? What would be better?! For me, this dish is like an even better take on the classic steak side, creamed spinach. It’s perfect served alongside my Garlic Butter Steak Tips.
After cooling, cover the casserole dish with aluminum foil or transfer your leftovers into an airtight container and place it in the fridge for up to 5 days. To reheat, pop it back in the oven at a lower temperature, around 300°F, until warmed through. If you’re in a hurry, individual portions can be reheated in the microwave for 1-2 minutes.
Yes, you can freeze this casserole. Just know that the texture of the zucchini and the cream sauce may break or change slightly upon defrosting and reheating. Store it in an airtight container in the freezer for up to two months, and when you’re ready to eat, let it thaw overnight in the fridge, then pop it back in the oven.
Zucchini naturally releases water as it cooks, which can result in a watery casserole. To avoid this, you can try salting and draining your zucchini slices before adding them to the casserole to draw out excess moisture!
No! The skin of the zucchini is soft and fully edible. Plus, it adds a nice pop of color to the dish. Just make sure to wash the zucchini thoroughly before slicing.
Absolutely! Just prepare the casserole as directed, but don’t bake it. Cover it tightly and store it in the refrigerator for up to a day ahead. When you’re ready, bake it as directed. You might need to add a few extra minutes to the baking time since it’s starting from the fridge.
