The Best Baked Buttercup Squash Casserole Recipe

Name: The Best Buttercup Squash Casserole Recipe
Prep time: 40 min
Cook time: 20 min
Ingredients: 4 cups buttercup Squash (cooked); 1/2 cup onion (diced); 4 TBSPS butter; 3 TBSPS garlic (fresh, minced); 1 pound ground beef (lean); 2 tsps salt; 1 tbsp italian seasoning; 2 green bell peppers (seeded and diced); 1 cup cheddar cheese (shredded)

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The best buttercup squash casserole recipe around. We take the sweet buttercup squash and top it with lean ground beef sautéed with onion and peppers. Filled with flavor this will be your new fall obsession.

A slice of casserole on a light blue plate with a fork beside it. The casserole contains ground meat and melted cheese on a bed of yellow ingredient, possibly mashed potatoes or squash. The rest of the casserole is in a glass dish in the background.

Buttercup or Kabocha squash are my favorite in the winter squash family. This squash with a dark green skin that sometimes favors a pumpkin is more like a sweet potato than a squash. But so much better for you. It causes very little spikes in blood sugar.

Roasting is good on its own but here we take it and make it into a beautiful full meal casserole. Handling and cutting winter squash can sometimes be the hardest part of using it in recipes, so check out our post on how to CUT AND COOK SQUASH. This method works well for any harder to handle squash.

Ingredients

While winter squash are seasonal, these kabocha or buttercup squash can be found in the produce sections of most supermarket chains like Publix. They keep well for weeks in a cool, dark, dry place. I process mine all season and freeze them to have over and over. All of the other ingredients are pantry and market staples that are easy to come by.

What You’ll Need

Buttercup or kabocha squash – this pumpkin looking squash has a sweet orange flesh that tastes like sweet potatoes and is perfect in my book!
Onion – we like using sweet yellow onion here to compliment the squash.
Butter – for healthy fat and tons of flavor. We like a quality butter like kerrygold.
Garlic – fresh and minced for a garlic flavor that is not overpowering.
Lean Ground Beef – we like using 90% lean or just slightly under for best results.
Salt – good sea salt or pink Himalayan are great mineral sources and wonderful to cook with.
Italian Seasoning – the dried blend of parsley, oregano, rosemary and basil.
Green Bell Peppers – any color will do but the green is not as sweet as the other colors and provides a balance to an already sweet dish.
Shredded Cheddar Cheese – what is a casserole without cheese? shredded cheddar not only matches the colors of this buttercup squash recipe but adds a bit of salty and earthiness to the dish.

A plate holds a square serving of a baked dish with ground meat and cheese, next to a metal fork. A baking dish with the remaining portions is partially visible in the top left corner. The setup is on a wooden surface.

See recipe card for quantities.

Instructions

We cook the squash ahead of time by carefully cutting, peeling and cubing it and placing the cut sides on a sheet pan lined with parchment paper. We roast it at 400 degrees for 30 to 45 minutes and then use it.

A person is spraying a transparent cooking spray into a glass baking dish on a wooden cutting board. The kitchen counter has various items, including a black bowl, a white bowl, and a small container in the foreground.

Lightly spray a 9×13 casserole dish with cooking spray. Preheat the oven to 350.

A person holds a white bowl of mashed yellow ingredients over a wooden cutting board. A clear rectangular glass baking dish is on the cutting board. Other kitchen utensils and cookware are visible in the background.

Mash the cooked kabocha or buttercup squash in a bowl with 2 tablespoons of the butter. Mix well.

A person wearing a smartwatch is mashing cooked yellow squash with a white spatula in a glass baking dish. The dish is on a wooden cutting board placed on a kitchen counter. A black frying pan and a red pot are in the background.

Spread the mashed squash evenly on the bottom of the prepared pan.

A top view of a stove with a red covered pot on the left burner, a non-stick frying pan with a slotted spoon and melting butter on the center burner, and a glass baking dish with a yellow baked dish on the right. A hand is adjusting the burner knob.

Melt the other 2 tablespoons of butter over medium heat.

A stove with a red pot on the left burner, a frying pan with chopped red onions and green bell peppers in the center, and a glass baking dish filled with a yellow mashed potato layer on a wooden surface to the right. A hand is operating the stove.

Sauté the chopped onions and bell peppers just until softened.

A person is scooping a spoonful of minced garlic into a frying pan containing chopped vegetables. The pan sits on a stove next to a red pot, while a baking dish filled with a yellow mashed topping is placed on a wooden cutting board.

Add in the garlic and cook a minute more. Stirring to prevent burning.

A person is holding a bowl of raw ground meat over a frying pan that contains onions and other ingredients. To the left, a red pot is on the stove. To the right, a baking dish filled with a yellow mashed mixture is on a wooden cutting board.

Add in lean ground beef to the onion mixture.

A person seasons ground meat in a frying pan with a pepper grinder on a stove. To the left is a red pot with a lid, and to the right is a square baking dish filled with a yellow mixture, possibly mashed potatoes. The scene is viewed from above.

Brown beef with onions and peppers. Once brown season with salt.

A person's hands seasoning ground beef and vegetables cooking in a pan on a stovetop. There is a red pot on the left burner and a rectangular dish with a yellow mixture on a wooden cutting board to the right.

Season with Italian seasoning.

A slotted spoon is transferring a mixture of ground meat from a pan into a glass baking dish containing a layer of mashed yellow potatoes. A pepper grinder and a salt shaker are placed next to a bag of ingredients on a wooden cutting board.

Spoon meat mixture evenly over prepared squash in the casserole pan.

A person is sprinkling shredded cheese from a package onto a dish in a clear glass baking dish. The dish appears to be on a wooden cutting board placed on a stovetop. A spatula rests nearby on the cutting board.

Top with shredded cheddar cheese.

A glass baking dish filled with a casserole covered with shredded cheese is on a wooden cutting board. In the foreground, a hand holds a partially visible bag of shredded cheddar jack cheese, preparing to add more cheese to the dish.

Bake in preheated oven for 15 to 20 minutes until cheese has melted and is slightly brown.

A portion of a cheesy meat casserole on a light blue plate. The dish appears to contain ground beef, cheese, and a yellow, possibly potato-based layer. A silver fork rests on the plate beside the casserole. The edge of the baking dish is visible in the background.

Allow to sit for 5 minutes or so before serving.

Why Brooke loves this recipe!

Recipes are like antiques. They are meant to be handed down from one generation to another. Each one holding a special memory or nostalgic memory. Here is why we love this one!

I love sweet potatoes but truthfully they can cause spikes in blood sugar sometimes. The kabocha and buttercup squash were introduced to me by my sweet friend Margaret and her Mother, Patsy. This is a wonderful substitute that won’t feel like one at all.

A slice of casserole with ground meat and melted cheese on a light blue plate with a fork. A larger, partially cut casserole sits in a glass baking dish in the background on a wooden surface.

Substitutions

Here are some ideas for other ingredients that may be helpful.

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Squash – if you can’t find butterCUP or kabocha, feel free to use acorn, butterNUT or even traditional yellow squash.
Butter – if you are watching what you are doing with butter, avocado oil is a great substitute. High smoke point and adds no flavor to the dish.
Beef – this recipe would work very well with ground chicken, turkey and even pork. Any substitutions will cause the nutritional values to change though.

Variations

I can think of a dozen ways to change this recipe up. All of them would be equally good as the original. Here are a few.

Spicy -adding chili or banana peppers instead of bell peppers would really kick things up. Also seasoning with cayenne or your favorite creole seasoning would also be wonderful.
More Veggies – adding in drained tomatoes, eggplant or even kale or other greens during the saute’ would be a great option to add more interest.
Spaghetti squash – adding spaghetti squash to the bottom of this would provide more of a crust like bottom, especially if you cooked it in the bottom of the casserole dish just a bit before topping and the final cook. Yum!

Equipment

🔧 I love to share recipes that are no special equipment required but here are a few things that would definitely make this recipe easier!

Storage and Reheating

This casserole keeps well in an airtight container for up to a week. Reheat in a low temperature oven until warmed through.

It also freezes well wrapped tightly for up to 3 months. Thaw in the refrigerator and reheat in a low oven.

A slice of layered casserole with ground meat and melted cheese is served on a gray plate with a fork on the side. The remaining casserole is in a rectangular glass dish on a wooden surface in the background.

⭐ LOVE THIS RECIPE? It would mean so very much to me if you would take a moment to rate this recipe and leave me a sweet comment in the recipe card below! ❤️❤️We hope you love all of the Southern and healthy recipes we share here at The Buttered Home and would love to see you back here often!

A portion of a casserole made with ground beef, melted cheese, and another ingredient, possibly potatoes or pasta, is served on a plate with a fork. The baking dish containing the remaining casserole is visible in the background.

The Best Buttercup Squash Casserole Recipe

Our buttercup squash casserole is a complete meal. Filled with lean ground beef, sweet buttercup squash, cheese and savory seasonings, this comforting casserole is perfect for Fall and the holidays.

Prep Time 40

Cook Time 20

Serving Size

Ingredients

4 cups buttercup Squash cooked
1/2 cup onion diced
4 TBSPS butter
3 TBSPS garlic fresh, minced
1 pound ground beef lean
2 tsps salt
1 tbsp italian seasoning
2 green bell peppers seeded and diced
1 cup cheddar cheese shredded

Instructions

Cut and roast or boil buttercup squash until tender. Mash flesh of squash with 2 tbsps butter and mix well. Spread evenly on to the bottom of a 9 x 13 casserole pan.
4 cups buttercup Squash, 4 TBSPS butter
Saute chopped onion and bell pepper in other 2 tbsps of butter until softened. Mix in garlic and cook for one minute. Add lean ground beef and brown with sautéed vegetables. Season with salt and Italian seasoning. Drain if needed.
1/2 cup onion, 4 TBSPS butter, 3 TBSPS garlic, 1 pound ground beef, 2 tsps salt, 2 green bell peppers, 1 tbsp italian seasoning
Layer the meat mixture on top of the squash in the casserole pan. Top with cheese.
1 cup cheddar cheese
Bake at 350 F for 15 to 20 minutes until cheese is melted and top is slightly brown.

See How To Make It!

🍴 PRO TIP!

Don’t be afraid to cut winter squash. If you followed the link above on how to cut and cook squash you will see all you need is about 4 minutes and a microwave. Cooking in the microwave for a few minutes softens even the toughest of squash that allows for easy cutting.

🗹 RECIPE FAQ’S

Is ButterCUP squash different than Kabocha?

They are very close to one another in appearance, size and texture. The kabocha doesn’t tend to have a dark bottom and has a slightly drier texture to the flesh than buttercup. Both are asian and often can be interchanged in recipes for them.

Is ButterCUP the same as ButterNUT squash?

They are both winter squash but look very different. The butternut has an oblong almost gourd shape while the buttercup favors a pumpkin. Both are sweet and low glycemic but also have a different texture. Butternut is more dense and not as porous. Also these can be interchanged in most recipes as the flesh favors in color.

How long will kabocha or buttercup squash last?

Both can be stored in a cool, dark and dry place for up to two months before cutting and using.