 This Slow Cooker Spaghetti Casserole Will Blow Your Mind – No Need to Boil Pasta!
If you’re tired of juggling multiple pots and pans just to make a comforting pasta dish, this recipe is about to change your dinner game forever.
Introducing the Slow Cooker Spaghetti Casserole — a dump-and-go masterpiece that’s loaded with savory meat, rich tomato flavor, and melty cheese, all without pre-boiling the pasta!
Whether you’re feeding a family or craving a cozy one-pot dinner, this is your new go-to.
Why You’ll Love This Recipe
- No need to boil the pasta separately!
- Made entirely in the slow cooker – minimal cleanup.
- Perfect for busy weeknights or lazy Sundays.
- Rich, cheesy, and packed with comforting Italian flavor.
- Budget-friendly and family-approved.
 Ingredients You’ll Need
For the Meat Sauce:
- 1 lb ground beef
- 1 medium onion, diced
- 2 garlic cloves, minced
- 1 (24 oz) jar marinara sauce
- 1 (14.5 oz) can diced tomatoes, drained
- 1 (8 oz) can tomato sauce
Spices & Seasoning:
- 1 tsp dried basil
- 1 tsp dried oregano
- ½ tsp red pepper flakes (optional but recommended)
- Salt & black pepper, to taste
For the Pasta & Topping:
- 8 oz uncooked spaghetti, broken in half
- 2 cups shredded mozzarella cheese
- ½ cup grated Parmesan cheese
- ¼ cup fresh chopped parsley (optional, for garnish)
 Step-by-Step Instructions
1. Brown the Beef
In a large skillet over medium heat, brown the ground beef along with the diced onion and garlic. Cook until the beef is no longer pink and the onions are soft. Drain any excess fat.
Tip: Want deeper flavor? Use Italian sausage or a mix of beef and sausage.
2. Build the Base in the Slow Cooker
Transfer the cooked meat mixture to your slow cooker. Add the marinara sauce, diced tomatoes, tomato sauce, basil, oregano, red pepper flakes (if using), salt, and pepper. Stir well to combine.
3. Add the Spaghetti
Break the uncooked spaghetti in half and gently stir it into the sauce, ensuring the noodles are well coated and submerged.
Important: Make sure no dry pasta is sticking out of the sauce, or it may cook unevenly.
4. Slow Cook to Perfection
Cover the slow cooker and cook on LOW for 3 to 4 hours, or until the spaghetti is tender.
Be sure to stir once halfway through to keep the pasta from sticking together or clumping.
5. Cheese It Up!
About 15 minutes before serving, sprinkle the mozzarella and Parmesan cheese over the top. Cover again and cook until the cheese is melted and bubbly.
6. Garnish & Serve
Top with freshly chopped parsley if you like, then serve warm. This casserole pairs perfectly with garlic bread and a simple green salad.
Time Breakdown
- Prep Time: 10 minutes
- Cook Time: 3–4 hours (on LOW)
- Total Time: ~3 hours 10 minutes to 4 hours 10 minutes
Nutrition (Per Serving)
Approx. 450 calories
High in protein, comforting carbs, and ooey-gooey cheese.
Optional Add-Ins
- Add chopped mushrooms, spinach, or bell peppers for extra nutrition.
- Use ground turkey or chicken for a lighter option.
- Swap in gluten-free spaghetti if needed.
Storage & Meal Prep Tips
- Refrigerate: Store leftovers in an airtight container for up to 3 days.
- Freeze: Let it cool completely, then freeze in portions for up to 1 month.
- Reheat: Microwave or bake until heated through. Add a splash of marinara if it seems dry.
Pro Tips for Success
Stir halfway to prevent sticking.
Don’t overcook – check the pasta at 3 hours.
Use a high-quality marinara sauce for the best flavor.
Save This Recipe & Share It!
If you’re loving this one-pot wonder, bookmark it now and share it with fellow pasta lovers! It’s the perfect lazy-day dinner that feels like a hug in a bowl.