Zucchini Casserole

Zucchini casserole is a satisfying, crowd-pleasing dish that never goes out of style. It’s summers answer to winter’s

green bean casserole

—cheesy, rich, and decadent, but with sliced zucchini adding freshness and lightness to the dish.

To keep this zucchini casserole tender and filling, you’ll need to salt the zucchini. Salting the zucchini for a few minutes draws out a bit of its excess moisture so that the casserole doesn’t get watery. Fresh zucchini gets to a crisp-tender texture and does not mush out when cooked this way.

The casserole’s creamy filling makes everything wonderfully cheesy, and the crunchy topping is savory and buttery. It has all the flavors you love in the

classic side

, thanks to Ritz crackers and fried onions. Pull this up alongside grilled chicken, steaks, or other vegetables for the perfect

summer side

.

Ingredients for Zucchini Casserole

Tender zucchini creates a base for this casserole, with mayonnaise, sour cream, and extra-sharp Cheddar adding a rich creaminess to the dish. A buttery cracker and fried onion topping takes it all to the next level.

To make zucchini casserole, you’ll need:

• 
  Cooking spray:
  
  To coat the baking dish to prevent the casserole from sticking.
• 
  Medium zucchini:
  
  The tender, fresh base of the casserole.
• 
  Kosher salt:
  
  Enhances the flavor of the zucchini, while helping to draw out excess moisture.
• 
  Sour cream:
  
  Adds a creamy, tangy flavor and texture to the casserole.
• 
  Mayonnaise:
  
  Helps bind the ingredients, while adding richness to the dish.
• 
  Black pepper:
  
  For a hint of peppery spice.
• 
  Large eggs:
  
  Binds and gives the casserole its structure.
• 
  Garlic cloves:
  
  Adds a savory depth.
• 
  Extra-sharp Cheddar:
  
  For a sharp, cheesy flavor that turns this casserole into total comfort food.
• 
  Grated Parmesan cheese:
  
  Adds a nutty, umami-rich flavor to the dish.
• 
  Buttery crackers:
  
  For a crunchy, buttery topping that contrasts the creaminess of the casserole.
• 
  Canned fried onions:
  
  Joins the crackers for a a crisp, savory topping with rich onion flavor.
  
  

How To Choose the Best Zucchini

This zucchini casserole highlights the tender texture and mild flavor of fresh zucchini. To choose the best zucchini at the market, keep these tips in mind:

• 
  Size:
  
  Medium-sized zucchini are often more flavorful and tender compared to larger zucchini.
• 
  Color:
  
  Look for zucchini with a dark green color, and glossy, smooth skin without blemishes.
• 
  Firmness:
  
  Zucchini should be firm to the touch, but with a very slight yield. They shouldn’t be mushy or soft.
• 
  Weight:
  
  Zucchini should feel heavy for their size.

Note that the peak season for zucchini is typically late spring through summer, and you’ll want to use your zucchini within a few days of purchasing for the freshest flavor and texture.

How To Make Zucchini Casserole

Salting the zucchini draws out excess moisture, helping you avoid a soggy result. Full instructions are below, but here’s a brief recap before you get started:

• 
  Step 1. Prepare oven and baking dish:
  
  Preheat oven, and spray to coat an 11- x 7–inch baking dish.
• 
  Step 2. Cut and salt zucchini:
  
  Cut zucchini into quarters, then into 1/2-inch slices. Toss with salt in a large bowl. Pour onto a double layer of paper towels and let stand 10 minutes.
• 
  Step 3. Assemble casserole and bake:
  
  In same bowl, whisk together sour cream, mayonnaise, pepper, eggs, and garlic. Stir in cheeses. Pat zucchini dry and stir into sour cream mixture. Pour into baking dish, cover with foil, and bake for 35 minutes.
• 
  Step 4. Add topping:
  
  Uncover baking dish and sprinkle casserole with crackers and onions. Bake until topping is browned.

Zucchini Casserole Variations

To change up this zucchini casserole, consider these variation ideas:

• 
  Herbs:
  
  Add chopped parsley, basil, or dill for an herbaceous touch.
• 
  Heat:
  
  Sprinkle red pepper flakes or cayenne pepper into the filling for a spicy twist.
• 
  Spice:
  
  For additional flavor, add paprika, onion powder, or Italian seasoning into the mix.
• 
  Veggies:
  
  Add extra nutrients to this casserole with chopped bell peppers, mushrooms, spinach, or broccoli.
• 
  Protein:
  
  Stir in crispy bacon, shredded chicken, or other favorite proteins for a one-dish meal.
• 
  Cheese:
  
  Swap the Cheddar with Gruyère, Monterey Jack, or other preferred cheeses.
• 
  Topping:
  
  Replace the buttery crackers with panko breadcrumbs mixed with melted butter as an alternative topping.

How To Prevent A Watery Zucchini Casserole

If you’ve had a watery

squash casserole

in the past, it’s a hard memory to shake. The good news is, this casserole shouldn’t have that problem. Slicing and salting the zucchini before using is a great way of infusing flavor into the zucchini, while drawing out excess moisture.

Zucchini has a high water content, and by salting, a high concentration of salt remains on the surface of the zucchini, while the inside has a much lower concentration. To balance, water inside the zucchini moves out to the surface, in a move known as osmosis. The paper towels placed beneath the zucchini then soak up the excess liquid.

While we don’t recommend it for this recipe, you can rinse off the salt before using the zucchini, if desired. If you do rinse, make sure to thoroughly dry the zucchini with paper towels before using in the casserole.

Can I Make Zucchini Casserole Ahead?

Prepare the filling of this casserole up to two days in advance, and refrigerate, covered, in the baking dish. For the crispiest topping, top with the buttery cracker topping on the day of serving before baking as directed.

You can also prepare the casserole fully without baking, wrap tightly, and freeze for up to three months. Thaw at room temperature before baking as directed.

How To Store and Reheat Leftover Zucchini Casserole

Store leftover zucchini casserole well-wrapped or in an airtight container in the refrigerator for up to four days, or freeze for up to three months. Thaw overnight in the refrigerator if frozen. Reheat, covered, in a preheated 350°F oven, uncovering in the last few minutes of baking to allow the top to crisp up.

You can also reheat small portions in the microwave or in a skillet on the stovetop. Avoid overcooking the casserole, which could cause a soggy texture, but do bring the internal temperature to 165°F.

What To Serve With Zucchini Casserole

To round out the meal, serve zucchini casserole with grilled or roasted chicken, baked fish,

pork chops

, or other favorite proteins. Complete the meal with rice, garlic bread, crusty bread, or your

favorite summer sides

.

More Sweet and Savory Zucchini Recipes You’ll Love

Add a nutritious boost to a variety of dishes by incorporating fresh zucchini into these sides, entrees, and desserts:

• 
  Zucchini Bread
  
• 
  Baked Zucchini Fries
  
• 
  Zucchini Muffins
  
• 
  Zucchini Fritters
  
• 
  Zucchini Cake
  
• 
  Zucchini Lasagna
  
• 
  Zucchini Pie
  
  
  
• 
  Air Fryer Zucchini Chips
  

Editorial contributions by

Katie Rosenhouse.