Baked Keto Spaghetti

Why This Low Carb Spaghetti Casserole Is on Repeat

This is the casserole I reach for when I want comfort food that doesn’t take all afternoon. The seasoned beef simmers in low-carb marinara while I prep the noodle layer, and once it’s assembled it goes straight into the oven. Two layers of cheese get bubbly and golden on top while the meat sauce underneath stays thick and rich.

It’s gluten-free and grain-free, so everyone eats the same dinner. I don’t have to make a separate plate for anyone, which on a weeknight is everything.

Reader Fatima has made this four times now and confirmed what I’ve always found: browning the beef until the edges crisp before adding the marinara makes the sauce cling differently and the casserole holds its shape better when you slice it. I do this every time.

If you like Italian-style casseroles, this pairs well with my keto skillet lasagna and Italian keto chicken and rice for a full weeknight rotation.

How I Season the Meat Sauce

I keep the filling straightforward: ground beef, cheese, and sauce. I brown the beef over medium-high heat, then stir in Italian seasoning and garlic powder. If you don’t have Italian seasoning on hand, a mix of dried basil and oregano does the job.

Don’t skip the garlic powder. I actually prefer roasting a whole bulb of garlic until it’s caramelized and sticky, then stirring that into the beef. It gives the sauce a deeper, sweeter garlic flavor that I think makes this casserole stand out. It’s an extra step but I do it every time now.

I toss in some diced onions too. Even a small handful adds good background flavor to the beef.

You can also swap in ground turkey, Italian sausage, or even leftover chicken. I’ve tried all three and the turkey version is what I reach for when I want something a little lighter. If you like Tuscan chicken pasta, the chicken swap will feel familiar.

Which Low Carb Noodles Work Best

I’ve tested this casserole with every low-carb noodle I could find: hearts of palm, zucchini noodles, spaghetti squash, and shirataki. Each one gives a slightly different result.

I used hearts of palm noodles here because they hold their shape the best after baking. They don’t get soggy like zucchini noodles can, and they don’t have the rubbery texture or smell of shirataki. Plus they’re naturally gluten-free.

If you go with zucchini noodles, pat them dry with paper towels first. I mean really press them. They release a lot of water during baking, and if you skip this step your casserole ends up soupy instead of sliceable. I use the same technique in my keto zucchini lasagna.

Shirataki noodles have almost zero carbs, which is a big plus. I rinse them under hot water for a full minute, then dry them in a hot skillet before adding to the casserole. That gets rid of the packaging smell completely.

Choosing a Low Carb Pasta Sauce

The pasta sauce can make or break your carb count here. I stick with Rao’s or Yo Mama’s Marinara because both are low in sugar and taste like actual marinara, not ketchup. Always check the label because some brands sneak in 8-10g of sugar per serving.

If you can’t find either brand, plain tomato sauce works. I add my own Italian seasoning and a pinch of garlic powder to it, and it’s close enough.

I also stir in a spoonful of sour cream sometimes. It adds a subtle creaminess to the sauce that makes people ask what my secret ingredient is. If you like that idea, my mom’s keto spaghetti recipe uses a similar trick.

How to Freeze and Reheat This Casserole

This casserole is one of the best keto freezer meals I’ve made. I assemble the whole thing, bake it, let it cool completely, then wrap it tight in foil and freeze. It keeps for up to 3 months.

To reheat from frozen, I bake at 350 degrees for 45-50 minutes with the foil on, then remove the foil for the last 10 minutes to crisp up the cheese. If I remember to thaw it overnight in the fridge, I reheat at 350 for about 20 minutes.

I’ve started freezing individual portions in glass containers too. It’s faster to reheat a single serving than a whole casserole, and my husband grabs one for lunch when he’s working from home. If you’re into meal prep, check out my cheesesteak casserole for another one that freezes just as well.