Cheesy Yellow Squash Casserole Recipe

This healthy keto yellow squash casserole recipe has layers of roasted summer squash and creamy homemade cheese sauce. Just 5 minutes prep + 5 ingredients.

Full ingredients + instructions are on the recipe card at the end. Before you scroll or jump down, don’t miss the useful tips in the post!

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This yellow squash casserole recipe is a cheesy and delicious way to enjoy the summer squash that goes crazy every summer! It’s made with basic ingredients (only 5!) and takes just a few minutes to prep. Simply roast the squash, make the homemade cheese sauce, and then bake the cheesy squash casserole. Easy! And, this healthy keto summer squash casserole is naturally low carb.

If you like healthy squash casserole recipes like this one, but have a pile of green zucchini to use, you can make this same recipe with zucchini instead, or try zucchini gratin. Or if you have more yellow squash to use up, try stuffed summer squash boats, or replace zucchini with yellow squash in my recipes for roasted zucchini, zucchini roll ups, or keto zucchini bread. These two types of summer squash are interchangeable in almost any recipe.

What Is Baked Yellow Squash Casserole?

This low carb summer squash casserole recipe is made up of layers of roasted yellow squash and then topped with a homemade cheese sauce and baked together until bubbly golden brown.

Why You’ll Love This Yellow Squash Casserole Recipe

Delicate, cheesy flavor
Soft squash and creamy cheese sauce
Comes together in a few simple steps
Simple, common ingredients
Takes just 5 minutes to prep
Only 3.4 grams net carbs per serving

Cheesy yellow squash casserole in a baking dish

Summer Squash Casserole Ingredients

This section explains how to choose the best ingredients for yellow squash casserole, what each one does in the recipe, and substitution options. For measurements, see the recipe card below.

Summer squash – I used yellow squash, but you can also use zucchini!
Olive oil – Use an extra virgin olive oil.
Shredded cheese – I used cheddar, but any cheese you like will work. Try Swiss, Gruyere, or other keto cheeses.
Heavy cream – This makes a rich, thick cheese sauce. Don’t replace it with half and half or other keto milks, as the sauce will be too runny. If you’re sensitive to dairy milk (but cheese is okay), you can swap the cream with full-fat coconut milk.
Garlic – Use fresh or jarred garlic, either will work fine.
Sea salt & black pepper

How To Make Squash Casserole

This section shows how to cook squash casserole with step-by-step photos and details about the technique. For full instructions, see the recipe card below.

Roast squash. Slice yellow squash into 1/4 inch slices and season with olive oil, sea salt, and black pepper. Roast for 10-12 minutes.

Make cheese sauce. In a saucepan, combine cheddar cheese, heavy cream, garlic, sea salt, and black pepper. Heat until melted and smooth.

Cheese sauce in a saucepan for cheesy squash casserole

Assemble. Layer roasted squash in baking dish. Pour sauce over squash and sprinkle remaining cheddar cheese on top.
Bake. Bake the keto squash casserole until it starts to bubble, then broil for a few minutes until golden.

Baking dish with keto squash casserole before adding cheese sauce

Baked summer squash casserole out of the oven

Frequently Asked Questions

What do you do with an abundance of yellow squash?

You make the best yellow squash casserole, of course! This casserole is delicious, but it’s also a great way to use up some of the squash that’s going crazy in your garden.

Why is my squash casserole watery?

Because squash is made up of a lot of water, it will release a lot of water while it’s cooked. This is why we’re roasting the squash ahead of time, so that the water can release and it won’t make your yellow squash casserole watery.

Is yellow squash casserole keto?

Yes, this healthy baked yellow squash casserole is keto and low carb.

The full nutrition stats can be found below the recipe card, but each serving has just 3.4 grams net carbs.

Storage Instructions

Store leftover yellow squash casserole in the refrigerator for 3-4 days.

Can you freeze squash casserole?

Yes, you can freeze the casserole for 2-3 months. Let it thaw in the fridge, then stir well before reheating. You may need to stir it again after reheating, as the sauce texture can change.

Reheating instructions:

Reheat the casserole in a 350 degree F oven for best results.

What Goes With Squash Casserole?

Healthy yellow squash casserole recipes like this one just need a main dish! Here are some ideas:

You can also make easy squash casserole recipes with other types of squash, such as buffalo chicken spaghetti squash casserole or zucchini casserole.

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Ingredients

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Instructions

Tap on the times in the instructions below to start a kitchen timer while you cook.

Preheat the oven to 400 degrees F (204 degrees C). Line a baking sheet with parchment paper.
Slice the squash into 1/4 inch slices. Toss the slices in the olive oil, 1/2 teaspoon sea salt, and 1/4 teaspoon black pepper.
Place the squash slices in a single layer on the lined baking sheet. Roast for 10-12 minutes.
Layer the roasted squash in a 9×13 baking dish.
In a medium saucepan, combine 2 1/4 cups cheddar cheese, heavy cream, garlic, 1/4 teaspoon sea salt, and 1/8 teaspoon pepper and heat over medium heat, until melted and smooth.
Pour the sauce over the squash and sprinkle the remaining 1/2 cup cheddar cheese on top.
Bake at 375 degrees F (190 degrees C) for 20-25 minutes until the casserole starts to bubble. Switch to broil for 2-3 minutes until the cheese begins to crisp and golden.

Recipe Notes

Serving size: 1/12 of entire casserole

Nutrition Facts

Amount per serving. Serving size in recipe notes above.

Calories 200

Fat 17.1g

Protein 8.3g

Total Carbs 4.7g

Net Carbs 3.4g

Fiber 1.3g

Sugar 3.1g

Nutrition facts are provided as a courtesy. Have questions about calculations or why you got a different result? Please see our nutrition policy.

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