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Try our Mini Squash Casserole for an easy, delicious, and healthy weeknight meal! This simple recipe, ideal for one or two servings, combines seasonal produce for a nourishing, warming vegetarian dish that’s perfect for any occasion.

Enjoy this delightful squash casserole alongside rich Butter Swim Biscuits, a fresh Tomato Salad, or a bowl of savory French Onion Soup.

Why You’ll Love This Squash Casserole Recipe

  • Simple to Make: Few ingredients and easy-to-follow steps make this recipe a breeze.
  • Versatile: This casserole can serve as a main dish or a side, depending on your meal plan.
  • Nutritious: Squash is high in vitamins A and C, making this a healthy choice.
  • Customizable: You can easily modify the recipe to suit your tastes and dietary needs.
  • Perfect Portion: This small squash casserole is ideally sized for one or two people to relish, leading to minimized waste and maximum enjoyment.
a mini squash casserole in a small rectangular baking dish on a silver tray.

What Is A Squash Casserole?

A squash casserole is a comforting, versatile dish featuring tender, sweet squash baked with savory ingredients. Typically, sliced squash, onions, and peppers are combined with creamy elements like sour cream and cheese, then topped with a crispy breadcrumb crust. It’s a hearty side dish or main course, offering a balance of textures and flavors.

Ingredients

squash casserole ingredients on a kitchen counter.

If you have any ingredients leftover from this recipe, check out our Leftover Ingredients Recipe Finder.

  • Butter: Can be replaced with margarine or olive oil for different dietary needs.
  • Yellow Squash: You can substitute zucchini or another type of summer squash if you prefer.
  • Sour Cream: If you’re looking for a healthier alternative, Greek yogurt works well.
  • Mayonnaise: Vegan mayonnaise can be used for a dairy-free version.
  • Panko Bread Crumbs: For those adhering to a gluten-free diet, opt for gluten-free breadcrumbs. Use store-bought or homemade breadcrumbs. Alternatively, for a buttery, different texture, consider using crushed Ritz crackers as your topping. To do this, simply take 8 Ritz crackers and crush them to your desired consistency.

This is just an overview of the ingredients I used and why I used them. For the full recipe please scroll down to the recipe box at the bottom of the post.

Recipe Variations

  1. Go Spicy: If you like a little heat, add some finely chopped jalapeno or a dash of cayenne pepper to give the casserole a kick.
  2. Cheese Variety: Instead of cheddar, try a different cheese. A Monterey Jack or Colby cheese would melt beautifully, or you could try a smoked gouda for a unique flavor twist.
  3. Herb Boost: For extra flavor, stir in some fresh herbs. Basil, thyme, or parsley would all add a fresh, flavorful note to the casserole.
  4. Go Nutty: Add a crunchy topping by sprinkling some crushed almonds or walnuts over the casserole before baking. It adds a lovely contrast of textures and a boost of healthy fats and proteins to your dish.

Remember, the key to successful variations is maintaining the original proportions of the recipe to ensure proper cooking.

Choosing The Perfect Summer Squash For Your Casserole

When it comes to creating a mouth-watering squash casserole, selecting the right summer squash is key. Let’s explore when to buy, how to choose, and the best ways to store summer squash to ensure your casserole is as fresh and flavorful as possible.

Seasonality of Summer Squash: The peak season for summer squash is from June to August, when they are abundant in local farmers markets. In warmer regions, like California, they can be found as early as May. Outside this season, grocery stores usually stock varieties that are imported from farther away.

How to Buy Summer Squash: Handle with care! Summer squash is known for its sensitive, thin, and delicate skin that can be easily damaged. When transporting them home, take extra precautions to avoid any punctures or bruises. A pierced skin can lead to rapid decay, so ensuring they stay intact is crucial for longevity and freshness.

Storing Your Summer Squash: Proper storage is essential. Keep your summer squash cool and dry by placing them in the crisper drawer of your refrigerator. It’s best to wash them only right before you’re about to use them. Though they can be stored for up to 5 days, it’s advisable to use them sooner rather than later. Summer squashes tend to become soft and lose their firmness quickly after harvesting, affecting their texture and taste in your casserole.

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How To Make Squash Casserole

These step-by-step photos and instructions help you visualize how to make a mini squash casserole. See the recipe box below for ingredient amounts and full recipe instructions.

  1. Toast the breadcrumbs: Melt butter in a 10-inch skillet over medium heat. Add the panko breadcrumbs and cook, stirring often until the panko is golden brown, about 5 minutes. Remove the pan from the heat and transfer the breadcrumbs to a bowl to use later.
panko breadcrumbs toasting in a skillet.
  1. Cook the squash: Heat the oven to 350°F (177°C). Lightly butter a 5×7 inch baking dish and set it aside.
  2. Melt 1 tablespoon of butter in either a 10-inch skillet or a 12-inch skillet over medium heat. Add the sliced squash and salt and cook, stirring occasionally for about 10 minutes or until the squash is tender.

Pro Tip: As you begin to sauté the squash, you’ll notice that the pan seems full. However, don’t worry – as the squash cooks, it naturally reduces in size, allowing it to comfortably fit within the pan.

  1. Add the onions and bell peppers to the pan and cook, stirring frequently for 5 minutes.
  2. Incorporate the garlic into the dish, stirring it consistently for about 30 seconds. Once that time has elapsed, remove the pan from the stove.
yellow squash, onions, red bell peppers cooking in a skillet.
  1. Assemble the casserole: In a separate small bowl, give the egg a good whisk. Follow this by whisking in the sour cream and mayonnaise. Once that’s combined, stir in the shredded cheese.
egg, sour cream, mayonnaise, and shredded cheddar cheese in a small bowl.
  1. With a gentle hand, stir the egg mixture into the squash and vegetables directly in the pan.
a squash casserole filling simmering in a skillet.
  1. Bake: Take the squash mixture from the pan and transfer it into the prepared baking dish. Place the baking dish on a rimmed baking sheet to catch any possible spills.
unbaked squash casserole in a small baking dish.
  1. Incorporate shredded Parmesan cheese into the toasted breadcrumbs in your bowl, ensuring they’re well mixed. Next, evenly distribute this breadcrumb mixture over the top of your casserole. To finish, take 1 tablespoon of butter that’s been chopped into small pieces, and scatter them over the casserole.
  2. Position your casserole in the preheated oven and let it bake for about 20 to 25 minutes. You’ll know it’s done when the casserole has solidified and the topping has achieved a pleasing golden color.
  3. Cool: Once baked to perfection, remove the casserole from the oven. Before diving in, allow it to cool for a few minutes (typically around 5-10 minutes), this makes it more enjoyable and safer to eat.
a small squash casserole topped with breadcrumbs cooling on a kitchen counter.

Expert Tips

  • Preparation: Pre-cut your vegetables in advance to save time during the cooking process and gather your ingredients before starting.
  • Breadcrumbs: Toasting the breadcrumbs before adding them to the casserole can give an extra depth of flavor and an additional crunch, this is why I recommend it.
  • Cheese: While cheddar cheese is suggested in the recipe, feel free to experiment with your favorite types of cheese. A blend of different cheeses can bring a unique taste to the dish.
  • Baking Dish: Use a 5×7 inch baking dish when making this recipe.
  • Serving: Serve the casserole warm, as it brings out the best flavors. But remember, it’s equally delicious at room temperature.

Frequently Asked Questions

Can a squash casserole be made ahead?

Yes, indeed! This casserole offers the flexibility of being prepared in advance. Simply assemble it, cover, and store in the refrigerator for up to 3 days. When you’re ready to bake, allow the casserole to reach room temperature first, and then bake according to the instructions in the recipe.

Can I use other vegetables in a squash casserole?

Certainly! This casserole is quite versatile. You’re welcome to incorporate other vegetables such as carrots or zucchini to align with your taste preferences. However, to maintain the consistency of the filling, try to keep the total quantity of vegetables used consistent with the original recipe.

Can I use pre-shredded cheese in this casserole recipe?

While pre-shredded cheese can be a time-saver, it often contains anti-caking agents that can affect the texture of your casserole. For best results, I recommend shredding your own cheese.

Can I freeze squash casserole?

Definitely! To freeze leftover squash casserole, you first need to ensure that it has cooled down entirely. Following that, wrap it securely using plastic wrap or aluminum foil. Remember to label it with the date, then store it in the freezer, where it can remain for up to three months.
To enjoy your frozen casserole, transfer it from the freezer to the refrigerator and allow it to thaw overnight. When ready to serve, remove the coverings and reheat it in a preheated oven at 350 degrees F for around 25 minutes. However, keep in mind that the crust may not retain its original crispness after being frozen and then reheated.

Ways To Use Leftover Ingredients

If you have any ingredients leftover from this recipe, check out our Leftover Ingredients Recipe Finder or you might like to consider using them in any of these single serving and small batch recipes:

For more information on the cooking and baking dishes I use in our “recipes for one”, please visit our FAQ page.

For examples of the dishes used at One Dish Kitchen, please visit our Store page.

If you’ve tried this cheesy squash casserole recipe or any recipe on One Dish Kitchen please let me know how you liked it by rating the recipe and telling me about it in the comment section below.

Also, if you take a picture please tag us on Instagram (@onedishkitchen) we’d love to see it!


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Mini Squash Casserole

5 from 7 votes
Prep: 10 minutes
Cook: 40 minutes
Cool: 10 minutes
Total: 1 hour
Servings: 2 servings
Enjoy this easy and delicious small squash casserole recipe! Made with simple ingredients, this dish is perfect for a quick and healthy weeknight meal.

Ingredients 
 

  • 3 tablespoons salted butter , divided plus a little more for buttering the baking dish
  • ½ cup Panko breadcrumbs
  • 1 pound yellow squash (about 2 to 3 small yellow squash), sliced into ¼ inch slices and then cut into half moon shapes.
  • ¼ teaspoon kosher salt
  • ½ cup chopped onions
  • ½ cup chopped red bell peppers
  • 1 clove garlic , minced
  • 1 large egg
  • 2 tablespoons sour cream
  • 2 tablespoons mayonnaise
  • ½ cup shredded cheddar cheese
  • 2 tablespoons shredded Parmesan cheese

Instructions 

Toast the breadcrumbs

  • Melt 1 tablespoon of butter in a 10-inch skillet over medium heat. Add the breadcrumbs and cook, stirring often until the panko is golden brown, about 5 minutes. Remove the pan from the heat and transfer the breadcrumbs to a bowl to use later.

Make the casserole

  • Heat the oven to 350°F (177°C). Lightly butter a 5×7 inch baking dish and set it aside.
  • Melt 1 tablespoon of butter in either a 10-inch skillet or a 12-inch skillet over medium heat. Add the sliced squash and salt and cook, stirring occasionally for about 10 minutes or until the squash is tender.
    Pro Tip: As you begin to sauté the squash, you'll notice that the pan seems full. However, don't worry – as the squash cooks, it naturally reduces in size, allowing it to comfortably fit within the pan.
  • Add the onions and bell peppers to the pan and cook, stirring frequently for 5 minutes.
  • Incorporate the garlic into the dish, stirring it consistently for about 30 seconds. Once that time has elapsed, remove the pan from the stove.
  • In a separate small bowl, give the egg a good whisk. Follow this by whisking in the sour cream and mayonnaise. Once that's combined, stir in the shredded cheese.
  • Gently stir the egg mixture into the squash and vegetables directly in the pan.
  • Take the squash mixture from the pan and transfer it into the prepared baking dish. Place the baking dish on a rimmed baking sheet to catch any possible spills.
  • Incorporate shredded Parmesan cheese into the toasted breadcrumbs in your bowl, ensuring they're well mixed. Next, evenly distribute this breadcrumb mixture over the top of your casserole. To finish, take 1 tablespoon of butter that's been chopped into small pieces, and scatter them over the casserole.
  • Position your casserole in the preheated oven and let it bake for about 20 to 25 minutes. You'll know it's done when the casserole has solidified and the topping has achieved a pleasing golden color.
  • Once baked to perfection, remove the casserole from the oven. Before diving in, allow it to cool for a few minutes (typically around 5-10 minutes), this makes it more enjoyable and safer to eat.

Notes

Expert Tips
  • Preparation: Pre-cut your vegetables in advance to save time during the cooking process and gather your ingredients before starting.
  • Breadcrumbs: Toasting the breadcrumbs before adding them to the casserole can give an extra depth of flavor and an additional crunch, this is why I recommend it.
  • Cheese: While cheddar cheese is suggested in the recipe, feel free to experiment with your favorite types of cheese. A blend of different cheeses can bring a unique taste to the dish.
  • Baking Dish: Use a 5×7 inch baking dish when making this recipe.
  • Serving: Serve the casserole warm, as it brings out the best flavors. But remember, it’s equally delicious at room temperature.

Nutrition

Serving: 1serving, Calories: 439kcal, Carbohydrates: 24g, Protein: 11g, Fat: 35g, Saturated Fat: 16g, Polyunsaturated Fat: 8g, Monounsaturated Fat: 9g, Trans Fat: 1g, Cholesterol: 155mg, Sodium: 748mg, Potassium: 755mg, Fiber: 4g, Sugar: 8g, Vitamin A: 1241IU, Vitamin C: 42mg, Calcium: 150mg, Iron: 2mg

The information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for a professional nutritionist’s advice.

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9 Comments

  1. Hi Joanie, Made this last night for the first, but not last time. I didn’t have any cheddar or Ritz so I used Monterey Jack instead and replace ritz cracker with 1/2 c crushed cornflake and 2 tbsp melted butter. I am so happy with this recipe. You have out done yourself yet again. I love your recipes as much as I hate leftovers. Yours is the perfect website for one or two.

  2. Delicious casserole. I especially liked the crunchy crumb topping. The crunch was a nice compliment to the soft filling. The only thing I would do different would be to add a little salt and pepper or maybe some crushed red pepper to the mayo, sour cream mixture.

  3. I made this casserole last night and it had all the flavor I was excepting. I will be making this again.

  4. I just made the squash casserole. I mixed Zucchini withyellow squash. It is delicious. Only needed more salt. Thank you for providing the recipe others. I enjoy them so much.

  5. This was absolutely amazing! We loved it! We had it as a side dish with baked salmon, and it was plenty for the two of us. I used one yellow squash and one small zuccini. Next time we plan to make it and have as an a main dish, it was that good and we liked it that much!