The Best Spaghetti Squash Casserole with Ground Beef and Mozzarella 2025
When the air turns crisp, and the kitchen becomes the heart of the home, nothing beats the aroma of a bubbling casserole fresh from the oven. This Spaghetti Squash Casserole with Ground Beef is my answer to hearty, family-style comfort food—without the heavy carb load of traditional pasta bakes.
Picture this: tender strands of roasted spaghetti squash tossed in a rich, tomato-kissed beef sauce, all crowned with a golden, cheesy layer that stretches with every forkful. It’s satisfying, wholesome, and just happens to be naturally gluten-free. Whether you’re aiming for a lighter dinner or simply love experimenting with vegetables, this dish delivers both flavor and nutrition in a way that pleases everyone at the table.
Why This Recipe Works
This isn’t just another casserole—it’s a balanced marriage of texture, flavor, and nutrition:
- Lower-carb comfort: Swapping pasta for spaghetti squash means you can enjoy a generous portion without feeling overly full.
- Protein-rich & filling: Lean ground beef makes it satisfying, while vegetables add nutrients and volume.
- Meal-prep friendly: Holds up well in the fridge and freezer, making it perfect for busy weeknights.
- Versatile & customizable: Works with different proteins, cheeses, and flavor profiles.
Why Spaghetti Squash is a Game-Changer
If you’ve never cooked with spaghetti squash, it’s about to become your new favorite ingredient. Once roasted, its flesh naturally separates into long, spaghetti-like strands that mimic the look and twirl of pasta. But here’s the magic—it’s:
- Low in calories and carbs (about 42 calories and 10g carbs per cup)
- Rich in fiber, keeping you satisfied longer
- Packed with vitamins like A, C, and B6, plus minerals such as potassium and manganese
- Naturally gluten-free, making it an ideal pasta alternative for those with dietary restrictions
Ingredient Breakdown & Pro Tips
Here’s what you’ll need and why each ingredient matters:
1. Spaghetti Squash
- Tip: Choose one that feels heavy for its size with a firm, unblemished skin.
- Flavor note: Roasting enhances its natural sweetness and deepens flavor.
- Pro Trick: Roast cut-side down to allow caramelization and better moisture control.
2. Lean Ground Beef
- Why lean? Less fat means a cleaner flavor and reduced greasiness in the final dish.
- Tip: Season the beef during cooking—not after—so the seasoning absorbs into the meat.
3. Aromatics – Onion & Garlic
- The backbone of savory flavor. Sauté until fragrant to form a robust flavor base.
4. Diced Tomatoes & Tomato Paste
- Tomatoes bring acidity and freshness; tomato paste adds richness and body.
5. Marinara Sauce
- Adds moisture, sweetness, and complexity. A homemade or good-quality jarred version works.
6. Italian Seasoning
- A balanced blend of herbs that gives a classic, homestyle feel.
7. Mozzarella Cheese
- Melts into a perfect, gooey blanket. Freshly shredded melts better than pre-packaged.
Step-by-Step Cooking Guide
Step 1: Roast the Squash
- Preheat your oven to 400°F (204°C).
- Slice the spaghetti squash in half lengthwise and remove seeds.
- Drizzle with olive oil, season with salt and pepper.
- Place cut-side down on a parchment-lined baking sheet.
- Roast for 35–40 minutes, or until fork-tender.
Step 2: Cool and Scrape
- Let squash cool for 10–15 minutes before handling.
- Using a fork, gently rake the flesh into long strands. Avoid mashing—it should resemble pasta.
Step 3: Prepare the Beef Sauce
- Heat a skillet over medium heat.
- Add lean ground beef and cook until browned.
- Stir in diced onion and minced garlic; cook until onions are soft.
- Drain excess fat.
- Add diced tomatoes, tomato paste, marinara, and Italian seasoning.
- Simmer for 5 minutes to meld flavors.
Step 4: Combine Squash and Sauce
- Gently fold spaghetti squash strands into the beef sauce until evenly coated.
Step 5: Assemble the Casserole
- Preheat oven to 375°F (190°C).
- Transfer mixture to a casserole dish (or back into squash shells for a rustic presentation).
- Sprinkle generously with shredded mozzarella.
- Bake for 20 minutes until cheese is bubbly and golden.
Serving Suggestions
Pair with:
- Fresh side salad with vinaigrette to cut richness
- Roasted green beans or steamed broccoli
- Garlic bread or knots for those who don’t mind carbs
- Light red wine like Pinot Noir
Flavor Variations
- Mexican-style: Add cumin, chili powder, and top with cheddar.
- Mediterranean twist: Use oregano, olives, and feta cheese.
- Vegetarian version: Replace beef with sautéed mushrooms and lentils.
- Extra creamy: Stir in ricotta or cottage cheese before baking.
Storage & Reheating
- Fridge: Store in airtight containers for up to 4 days.
- Freezer: Freeze tightly wrapped portions for up to 2 months.
- Reheat: In a 350°F oven until warmed through or microwave in short intervals.
FAQ Section
Q: Can I make this dairy-free?
Yes! Use dairy-free mozzarella and ensure your marinara sauce is vegan.
Q: Can I prepare it ahead?
Absolutely. Assemble, refrigerate, and bake when ready.
Q: Does spaghetti squash taste like pasta?
Not exactly—it’s slightly sweet with a mild vegetable flavor but works beautifully in pasta-style dishes.
Q: How do I cut squash safely?
Microwave whole squash for 3 minutes to soften before slicing.
Nutrition Facts (Per Serving)
- Calories: 280
- Protein: 22g
- Carbs: 14g
- Fat: 14g
- Fiber: 4g
(Values are estimates and vary based on ingredients used.)
Common Mistakes & How to Avoid Them
- Overcooking squash – leads to mushy strands. Check at 35 minutes.
- Not draining beef – results in greasy casserole.
- Using watery tomatoes – strain diced tomatoes before adding.
Final Thoughts
This Spaghetti Squash Casserole with Ground Beef proves that comfort food can be indulgent and wholesome at the same time. It’s easy to prepare, endlessly adaptable, and perfect for both weeknight dinners and special family meals.
Once you try it, you’ll see why this recipe becomes a repeat favorite. Roasted squash adds natural sweetness, the beef sauce brings richness, and the cheesy topping ties it all together into one satisfying bite after another.
