Baked Low Carb Keto Spaghetti Casserole (Quick & Easy)
Baked Keto Spaghetti Casserole is the perfect alternative for your pasta cravings. Traditionally, Italian dishes are loaded with carbs, but you don’t have to miss out on your favorite dishes while eating a keto or low-carb diet! This dish is the perfect Keto comfort food!
I love spaghetti. It is always a go-to at our house for an easy weeknight meal. Since I always keep ground beef browned in my freezer, this Baked Low Carb Spaghetti Casserole comes together quickly on busy evenings when I really don’t feel like spending a lot of time in the kitchen.
It does take a little getting used to spaghetti squash as a low-carb, gluten-free pasta. alternative if you haven’t tried it. I will never say, it is “JUST LIKE THE REAL THING,” I’ve been tricked by that before with mashed cauliflower and mashed potatoes. Instead, it is a good substitute, and it really tastes delicious.
Ingredients
- Ground beef – I prefer to use 80/20 to add extra fat to this dish. You can also use ground Italian sausage or ground turkey for a low-carb substitute if you do not like ground beef.
- Onions – Onions add flavor and a little extra texture but can be left out to reduce carbs.
- Spaghetti squash – Spaghetti squash is a fabulous low-carb pasta alternative to noodles, and it is super delicious!
- Olive oil: Adds flavor to the spaghetti squash when roasting and allows the salt and pepper to stick to the squash.
- Parmesan and mozzarella cheese – Add to the top of the casserole for that delicious baked spaghetti flavor.
Below you’ll find a step-by-step pictorial for those who prefer visuals. Make sure to scroll to the bottom of the page for the recipe card with the detailed ingredients and instructions.
Step 1: Preheat the oven to 350, cut up your onion, add it to the large skillet with ground beef and cook until browned; drain the ground beef and add it back to the pan.
Tip: I keep ground beef already browned in my freezer in gallon freezer bags. I buy ground beef in bulk and brown all at once. Easy meal prep like this makes dinners much easier and saves a ton of time.
Step 2: Add low-carb marinara sauce to the skillet with ground beef on medium heat and stir occasionally. If your sauce becomes too thick, add beef broth until it reaches your desired consistency.
Low Carb Spaghetti or Pizza Sauce Options Without Any Added Sugar
Rao’s Homemade Marinara Sauce – 6g carbs – 1g fiber = 5g net carbs per ½ cup
Rao’s Homemade Tomato Basil Sauce – 6g carbs – 1g fiber = 5g net carbs per ½ cup
Lucini Italia Organic Tuscan Tomato Sauce – 5g carbs – 1g fiber = 4g net carbs per ½ cup
Lucini Italia Organic Rustic Tomato Basil – 5g carbs – 1g fiber = 4g net carbs per ½ cup
Victoria Trading Company Marinara Sauce – 6g carbs – 1g fiber = 5g net carbs per 1/2 cup
ALDI Selected Premium Marinara – 7g carbs – 2g fiber = 5g net carbs per ½ cup
Mezzetta Family Recipes Marinara – 7g carbs – 1g fiber = 6g net carbs per ½ cup
Classico Tomato & Basil Pasta Sauce – 8g carbs – 2g fiber = 6g net carbs ½ cup
Step 3: Cut the spaghetti squash in half and then use a spoon to scrape all the seeds. Coat the squash with olive oil, salt, and pepper, place skin side up on the pan, and roast. My family likes our spaghetti squash to be more al dente, so if you prefer yours to be softer, adjust the time accordingly. Once it has finished roasting, use a fork to shred the inside of the squash into strands for a spaghetti noodles substitute.
This next step is crucial! Place the roasted spaghetti squash on paper towels to squeeze out the moisture so that the keto spaghetti casserole will not be watery when it is baked. This step is VERY IMPORTANT.
Tip: Spaghetti squash is extremely tough to cut. To make this process easier, pierce the outside of the squash with a fork or knife several times and throw it in the microwave for approximately 3-5 minutes. This will soften the skin and make it easier to cut. For more detailed instructions, How to Roast Spaghetti Squash is a fantastic, thorough resource.
Step 4: Place the spaghetti sauce as the bottom layer in a 9×9 baking dish that has already been greased.
If it seems watery at all, drain it again on paper towels before adding the sauce.
Step 5: Next, spoon the low-carb meat sauce over the squash.
Step 6: Add the mozzarella, parmesan cheese, and Italian seasoning to the casserole and bake. Garnish with oregano and Enjoy!
I always top my casserole with fresh or dried parsley. It really gives it a restaurant-style homemade look.
How To Make This Ahead of Time
This baked keto spaghetti casserole can easily be made in advance! Follow all of the steps of assembling the casserole but hold off on baking. Instead, store in the refrigerator covered until you are ready to bake. Bake time may be a little longer coming out of the cold refrigerator, so keep that in mind! You may want to set it out on the counter for a bit before baking, so it isn’t quite as cold going into the oven.
Can I Make Homemade Pasta Sauce
Yes! The homemade meat sauce is often lower in carbs; however, it is not always the most convenient option for my family, so I often use jarred. If you want to make your own low-carb marinara sauce, here is one of my favorite recipes, Keto spaghetti sauce.
Yum! How delicious does this look? It is the perfect comfort food, and it doesn’t even taste low carb. We like to enjoy it with a nice big leafy garden salad along with keto cheesy garlic chaffles.
What do I serve with it?
- Keto Cheesy Garlic Chaffle Bread
- Keto Cheesy Breadsticks
- Steamed Broccoli
- Fresh Leafy Garden Salad
More Easy Keto Casserole Recipes
- Easy Spaghetti Sauce Lasagna Boats
- The BEST Easy Keto Baked Italian Sausage
- Keto Italian Meatball Casserole
Keto Spaghetti Squash Casserole
Ingredients
- 1 lb ground beef 80/20
- 1/3 onion chopped if you have one
- 24 oz spaghetti sauce no sugar added
- Spaghetti squash
- 2 cups Mozzarella cheese
- 1/2 cup Parm cheese
- 1 TB Olive oil
- Salt and pepper
- Parsley
Instructions
- Preheat oven to 350 degrees.
- Cut spaghetti squash in half and scrape out the inside. (pop it in the microwave first as it makes it easier to cut) Cover inside of the spaghetti squash with olive oil and sprinkle salt and pepper. On a cookie sheet covered with parchment paper, turn the spaghetti squash cut side down and roast for 20-35 min depending on the size of the squash until the inside is al dente when scrapped.
- Meanwhile, brown ground beef with onion, then drain. Add spaghetti sauce and simmer on low for 15 min. If it gets too high, you can add a bit of beef broth.
- Scrap the spaghetti squash with a fork, then place all of it inside several paper towels to squeeze out moisture. I did this twice with two sets of fresh paper towels so it wouldn't be watery.
- Grease a 9 x 9 square baking pan. Add spaghetti squash to the bottom of the casserole dish, top with spaghetti sauce, mozzarella cheese, and parm cheese.
- Baker in a 350 degrees oven until cheese melts for approx 5-10 min then turn oven to broil for 1-2 min and watch carefully as mozzarella cheese starts to bubble and brown a little.
- Top with parsley for pics to give some dimension for color. I added a few pics to document for ideas. If you have a larger spaghetti squash, you may not need to add all of it to the casserole dish.
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Notes
Low Carb Spaghetti or Pizza Sauce Options Without Any Added Sugar
- Rao’s Homemade Marinara Sauce – 4g net carbs per ½ cup
- Rao’s Homemade Tomato BasilSauce– 3g net carbs per ½ cup
- Lucini Italia Organic Tuscan Marinara Sauce – 3g net carbs per ½ cup
- Lucini Italia Organic Rustic Tomato Basil – 3g net carbs per ½ cup
- Mezzetta Napa Valley Homemade Marinara – 6g net carbs per ½ cup
- ALDI Simply Selected Premium Marinara - 5g net carbs per ½ cup
- Victoria Trading Company Marinara Sauce - 5g net carbs per 1/2 cup
- Victoria Trading Company Marinara Sauce - 5g net carbs per 1/2 cup
Tips:
- This is crucial. Make sure to squeeze all of the water out of the spaghetti squash. Place the roasted spaghetti squash on paper towels to squeeze out the moisture so that the keto spaghetti casserole will not be watery when it is baked. This step is VERY IMPORTANT.
- Spaghetti squash is extremely hard to cut. To make this process easier, pierce the outside of the squash with a fork or knife several times and throw it in the microwave for approximately 3-5 minutes. This will soften the skin and make it easier to cut.
You can also use Miracle Noodles, coconut noodles or Palmini hearts of palm noodles if you want less carbs and a more noodley texture.
Yes, there are lots of different options. Thanks for the feedback.
I just love ALL of your recipes!! It makes eating less sugar and carbs so much easier. I did add a bit of tomato paste to thicken the sauce so it’s not so runny.
So glad you enjoyed it. If you really press out all of the liquid from the spaghetti squash it helps it to thicken up. Or, if you boil the spaghetti sauce with the lid off it will reduce and thicken. But tomato paste is a good option too.
Can you freeze the Baked Low Carb Keto Spaghetti Casserole?
I’ve never frozen it so I can’t answer how it would turn out. If you try it let me know how it goes. Thanks
This was so great and easy to make. I had to cut the tomato sauce way down because I have to watch my potassium. I will definitely make again!
Awesome! So glad you loved it!
How much is a serving? Thanks
Hey Rodney, just evenly divide the entire casserole into 9 servings.