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This Mini Squash Casserole is rich, creamy, and topped with golden, crispy breadcrumbs. Made with tender squash and plenty of cheese, it’s flavorful comfort food that’s easy to make and perfectly portioned for one or two people.
Enjoy this small squash casserole with buttery Butter Swim Biscuits, a refreshing Tomato Salad, or a warm bowl of French Onion Soup.
Why You’ll Love This Recipe
- Rich and Creamy: This casserole has a creamy, cheesy filling that makes every bite rich and satisfying.
- Perfectly Crispy Topping: The buttery, toasted breadcrumb topping adds a crispy contrast to the soft, flavorful squash.
- Versatile Dish: It’s a versatile dish that works as both a main course and a hearty side.
- Quick and Easy: With simple ingredients and easy steps, it comes together quickly.
- Ideal for One or Two: This recipe is perfectly portioned for those cooking for one or two, so there’s no waste.
I love this mini squash casserole because it turns simple ingredients into something truly comforting. The combination of tender squash, melted cheese, and crispy breadcrumbs makes every bite satisfying. It’s the kind of dish that feels special without being complicated. Whether I’m making it for a quick weeknight meal or serving it alongside something else, it always delivers on flavor.
Ingredients
If you have any ingredients leftover from this small squash casserole recipe, check out our Leftover Ingredients Recipe Finder.
- Yellow Squash: The main ingredient in this casserole. Choose small to medium squash with firm, smooth skin for the best texture and flavor. Avoid squash with bruises or soft spots, as they spoil quickly. Zucchini or another type of summer squash can be used instead.
- Butter: Adds richness to the casserole. You can use margarine or olive oil if needed.
- Sour Cream: Adds creaminess and a slight tang. Greek yogurt is a good substitute.
- Mayonnaise: Helps create a rich, creamy texture.
- Panko Bread Crumbs: Creates a crispy topping. You can also use crushed Ritz crackers for a buttery crunch—just crush about 8 crackers.
Recipe Variations
Customize your casserole with these simple variations:
- Add Some Heat: Mix in finely chopped jalapeño or a pinch of cayenne for a spicy version.
- Try Different Cheese: Swap cheddar for Monterey Jack, Colby, or smoked gouda for a new flavor.
- Boost with Herbs: Stir in fresh basil, thyme, or parsley for extra freshness.
- Add Crunch: Sprinkle crushed almonds or walnuts on top before baking for a crispy texture.
How To Make Squash Casserole
These 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.
- Toast the Breadcrumbs:
- Melt butter in a 10-inch skillet over medium heat. Add the panko breadcrumbs and cook, stirring often, until golden brown, about 5 minutes. Transfer to a bowl and set aside.
- Cook the Squash:
- Preheat 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 a 10- or 12-inch skillet over medium heat. Add the sliced squash and salt. Cook, stirring occasionally, for about 10 minutes until tender. (The pan may seem full at first, but the squash will shrink as it cooks.)
- Add the Vegetables:
- Stir in the onions and bell peppers. Cook for 5 minutes, stirring frequently.
- Add the garlic and cook for 30 seconds, stirring constantly. Remove from heat.
- Make the Egg Mixture:
- In a small bowl, whisk the egg. Add sour cream and mayonnaise, whisking until smooth. Stir in the shredded cheddar cheese.
- Assemble the Casserole:
- Gently stir the egg mixture into the cooked squash and vegetables.
- Transfer the mixture to the prepared baking dish. Place the dish on a rimmed baking sheet.
- Add the Topping:
- Mix shredded Parmesan into the toasted breadcrumbs. Sprinkle evenly over the casserole.
- Dot with 1 tablespoon of butter, cut into small pieces.
- Bake:
- Bake for 20-25 minutes, until the casserole is set and the topping is golden brown.
- Cool & Serve:
- Let the casserole cool for 5-10 minutes before serving.
Expert Tips
- Prep Ahead: Slice the squash, chop the onions and peppers, and gather all ingredients before you start cooking. This makes the process smoother.
- Toast the Breadcrumbs: This step adds extra crunch and enhances the flavor, so don’t skip it.
- Use the Right Baking Dish: A 5×7-inch baking dish is the perfect size for this recipe.
- Let It Cool: The casserole is best served warm, but it also tastes great at room temperature.
- Storage & Reheating: Store leftovers in an airtight container in the fridge for up to 3 days. Reheat in the oven at 300°F to maintain the texture.
Frequently Asked Questions
Yes! Zucchini works just as well in this casserole, or you can mix both for variety.
Yes, you can assemble it up to a day in advance and store it in the refrigerator. Add the breadcrumbs just before baking for the best texture.
Yes. To freeze leftover squash casserole, let it cool completely, then wrap it tightly in plastic wrap or aluminum foil. Label it with the date and store it in the freezer for up to three months.
When ready to eat, transfer the casserole to the refrigerator and let it thaw overnight. Remove the wrapping and reheat in a 350°F oven for about 25 minutes. The topping may lose some of its crispness after freezing and reheating.
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:
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!
Mini Squash Casserole
Equipment
Ingredients
- 3 tablespoons salted butter -divided plus a little more for buttering the baking dish
- ½ cup Panko breadcrumbs
- 1 pound yellow squash sliced into ¼ inch slices and then cut into half moon shapes – (about 2 to 3 small yellow squash)
- 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 panko and cook, stirring often, until golden brown, about 5 minutes. Transfer to a bowl and set aside.
- Cook the Squash: Preheat 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 a 10- or 12-inch skillet over medium heat. Add the sliced squash and salt. Cook, stirring occasionally, for about 10 minutes until tender. (The pan may seem full at first, but the squash will shrink as it cooks.)
- Add the Vegetables: Stir in the onions and bell peppers. Cook for 5 minutes, stirring frequently.Add the garlic and cook for 30 seconds, stirring constantly. Remove from heat.
- Make the Egg Mixture: In a small bowl, whisk the egg. Add sour cream and mayonnaise, whisking until smooth. Stir in the shredded cheddar cheese.
- Assemble the Casserole: Gently stir the egg mixture into the cooked squash and vegetables.Transfer the mixture to the prepared baking dish. Place the dish on a rimmed baking sheet.
- Add the Topping: Mix shredded Parmesan into the toasted breadcrumbs. Sprinkle evenly over the casserole.Dot with 1 tablespoon of butter, cut into small pieces.
- Bake: Bake for 20-25 minutes, until the casserole is set and the topping is golden brown.
- Cool & Serve: Let the casserole cool for 5-10 minutes before serving.
Notes
- Prep Ahead: Slice the squash, chop the onions and peppers, and gather all ingredients before you start cooking. This makes the process smoother.
- Toast the Breadcrumbs: This step adds extra crunch and enhances the flavor, so don’t skip it.
- Use the Right Baking Dish: A 5×7-inch baking dish is the perfect size for this recipe.
- Let It Cool: The casserole is best served warm, but it also tastes great at room temperature.
- Storage & Reheating: Store leftovers in an airtight container in the fridge for up to 3 days. Reheat in the oven at 300°F to maintain the texture.
Nutrition
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.
I never get tired of eating this, even though I’m making it often, while my little garden produces summer squash. I don’t have yellow squash, but those round Mexican zucchinis (Tatume squash) work just as well. Love it!
Thank you so much for your feedback.