Zucchini and Squash Casserole Recipe: A Healthy, Comforting Classic

Looking for a flavorful, easy-to-make side dish that highlights fresh summer produce? This zucchini and squash casserole recipe brings together vibrant vegetables, a crispy Parmesan crust, and wholesome ingredients to create the perfect comfort food with a healthy twist. Whether you’re preparing a holiday meal, hosting a summer cookout, or simply want to use up your garden zucchini, this recipe fits the bill.

Not only is this casserole a delicious way to eat your veggies, but it’s also seasonally smart. You can find out what’s in peak season near you using this helpful seasonal produce guide. Cooking with seasonal vegetables ensures the freshest flavors and best nutritional value.

Before you dive in, make sure you’re slicing your squash safely and evenly. A mandoline slicer is the best tool for consistent cuts, but it needs to be used carefully. For safety tips and proper usage, check out this resource on mandoline safety.

Why You’ll Love This Zucchini and Squash Casserole

• Low in carbs and high in flavor
• Naturally gluten-free (if you use gluten-free breadcrumbs)
• Perfect as a side dish or light vegetarian main
• Easy to customize with cheese, herbs, or added protein

Ingredients You’ll Need

• 2 lbs. zucchini and yellow squash (cut into ¼-inch slices)
• 2 ½ tbsp. olive oil (or avocado, sunflower, or safflower oil)
• 1 ¼ tsp. salt, divided
• ½ tsp. pepper
• ⅓ cup Parmesan cheese, grated (or dairy-free alternative)
• ⅓ cup Panko breadcrumbs (gluten-free if needed)
• ¼ tsp. garlic powder
• 2 tbsp. fresh parsley, finely chopped

Step-by-Step Instructions

1. Prep the Squash

• Wash and slice the zucchini and squash into uniform ¼-inch rounds.
• Sprinkle with ½ teaspoon salt and let sit for 10 minutes to draw out excess water.
• Pat dry with a paper towel to prevent sogginess in the casserole.

2. Assemble the Casserole

• Preheat the oven to 350°F.
• Lightly grease a 9-inch square baking dish.
• Arrange the squash slices in alternating layers (zucchini, yellow squash) to create a visually appealing pattern.

3. Add the Topping

• Mix Parmesan, breadcrumbs, and garlic powder in a small bowl.
• Drizzle olive oil over the layered squash and season with remaining salt and pepper.
• Sprinkle the breadcrumb mixture evenly on top.

4. Bake to Perfection

• Cover with foil and bake for 30 minutes.
• Uncover and broil on high for 3–5 minutes until golden and crispy.

Tips to Avoid a Watery Casserole

• Always salt and blot the squash before baking.
• Cut vegetables evenly to ensure they cook at the same rate.
• Avoid covering tightly during storage, as this traps steam.

Flavorful Variations

• Southern Style: Add crushed Ritz crackers and a bit of sour cream.
• Mediterranean: Mix in crumbled feta cheese, oregano, and cherry tomatoes.
• Vegan Version: Use plant-based cheese and vegan butter for the topping.
• Protein Boost: Layer in cooked quinoa, shredded chicken, or chickpeas.

Nutritional Highlights

• High in fiber, vitamin C, and potassium
• Low in calories and carbohydrates
• A great fit for keto, gluten-free, or vegetarian diets

Make-Ahead and Freezing Instructions

• To prep ahead: Assemble the casserole but don’t bake. Refrigerate up to 2 days.
• To freeze: Cool completely, wrap tightly with plastic wrap and foil, and freeze for up to 3 months.
• To reheat: Bake at 350°F until warmed through, or microwave individual servings.

Serving Suggestions

This zucchini and squash casserole pairs well with:

• Grilled or baked chicken (Hot Honey Chicken, Chicken Cordon Bleu)
• Seafood dishes like Lemon Garlic Baked Salmon or Panko Crusted Fish
• Red meat options like Air Fryer Steak or Filet Mignon

Expert Cooking Tips

• Use a mandoline for even slices, but be cautious with your fingers.
• Salt first to remove excess moisture and prevent a soggy casserole.
• Add Italian-seasoned breadcrumbs for extra flavor.
• Broil the casserole at the end to get a crispy, golden top.
• Don’t skip fresh herbs—they add brightness and freshness to the dish.

Common Mistakes to Avoid

• Cutting slices too thick or uneven
• Skipping the pre-salting step
• Using too much cheese, which can make the casserole greasy
• Overbaking, which turns the squash mushy

Frequently Asked Questions

Can you freeze zucchini and squash casserole?
Yes, after cooling completely, wrap tightly and freeze for up to 3 months. Reheat in the oven or microwave.

How do you keep squash casserole from getting watery?
Salt the sliced squash and blot dry before baking to release excess moisture.

Can I make this casserole vegan or dairy-free?
Absolutely—just swap in vegan cheese and gluten-free breadcrumbs.

What other vegetables can I add?
Try sliced eggplant, tomatoes, or bell peppers for variety.

Can I add meat to this casserole?
Yes! Add pre-cooked chicken, turkey sausage, or ground beef for a heartier version.

Final Thoughts

This zucchini and squash casserole recipe is as flexible as it is flavorful. It’s ideal for both weeknight dinners and festive holiday tables. With minimal ingredients and maximum taste, it’s a great way to enjoy the best of summer’s bounty all year long.

Let this dish inspire you to get creative in the kitchen—and never let zucchini season pass you by again!

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