Slow Cooker Spaghetti Casserole

There’s nothing quite as comforting as a big bowl of saucy, cheesy spaghetti, especially when it comes straight from the slow cooker. If you love creamy, flavorful, and easy-to-prepare meals, this Slow Cooker Spaghetti Casserole is about to become your new weeknight staple. Imagine layers of tender pasta, rich marinara, juicy ground beef, and gooey cheese all melded together, ready to serve with minimal fuss. Did you know that slow cookers were once considered a “miracle gadget” in the 1970s for making family meals effortless? This recipe takes the magic up a notch by turning classic spaghetti into a cozy casserole—perfect for busy families, potlucks, or anyone craving nostalgia. If you’ve ever enjoyed my Baked Ziti recipe, you’ll find this casserole delivers all the homestyle vibes with even less hands-on time. Get your forks ready—this is a family favorite you won’t want to miss!

What is Slow Cooker Spaghetti Casserole?

Let’s get one thing clear: Slow Cooker Spaghetti Casserole is not just spaghetti baked in a dish. It’s a love letter to pasta, delivered in silky, saucy layers from your trusty slow cooker! Why the funny name? Well, recipes like this one are perfect for anyone who wonders, “Can I make a classic like spaghetti even easier?” Spoiler alert: Yes, you can! Some say the way to a man’s heart is through his stomach—this dish might just win over the whole family. Think of it as spaghetti night with a twist, full of personality and charm. Ready for something deliciously different? Give this slow cooker wonder a try and see why everyone’s singing its praises!

Why You’ll Love This

First, the star of the show: this casserole combines the robust flavors of slow-simmered meat sauce and Italian herbs with irresistibly melty mozzarella and Parmesan. The slow cooker not only saves you time in the kitchen but also brings out a depth of flavor that tastes like you’ve been cooking for hours (even though you haven’t!). Making this dish at home is also a fantastic budget-saver; for a fraction of the price of restaurant pasta bakes, you’ll get a filling family meal with leftovers for days. Plus, tender spaghetti, tangy tomatoes, and a gooey cheese blanket make every bite something special. Compare it to my One-Pot Chicken Alfredo—the techniques may differ, but both boast simple steps and unforgettable flavor. Whichever you choose, you’re in for a treat! Don’t wait—gather your ingredients and whip up this Slow Cooker Spaghetti Casserole tonight.

How to Make

Quick Overview

If you’re looking for a crowd-pleasing dinner with minimal effort, this Slow Cooker Spaghetti Casserole checks every box. Its greatest asset is simplicity: just brown the meat, layer the ingredients, let your slow cooker do the heavy lifting, and enjoy a dish with all the flavors of classic baked spaghetti—no boiling or stirring required. In less than 20 minutes of prep and about 4 hours of hands-off cooking, you’ll have a cozy meal that’s both satisfying and fuss-free.

Ingredients

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
1 tsp dried basil
1 tsp dried oregano
1/2 tsp red pepper flakes (optional)
Salt and pepper, to taste
8 oz uncooked spaghetti, broken in half
2 cups shredded mozzarella cheese
1/2 cup grated Parmesan cheese
1/4 cup chopped fresh parsley (optional, for garnish)

Step-by-Step

1. In a large skillet over medium heat, brown the ground beef with the diced onion until the meat is no longer pink and the onion is soft, about 6-8 minutes. Add minced garlic in the last minute. Drain off any excess fat.
2. Transfer the cooked beef mixture to your slow cooker. Add the marinara sauce, diced tomatoes, tomato sauce, dried basil, dried oregano, and red pepper flakes. Stir to combine, then season with salt and pepper to taste.
3. Break the uncooked spaghetti in half and stir it into the sauce mixture in the slow cooker, making sure the noodles are completely covered by sauce.
4. Sprinkle 1 cup of mozzarella cheese and most of the Parmesan over the top, reserving some for the end.
5. Cover and cook on low for 3-4 hours, or until the spaghetti is tender. Stir gently halfway through if desired, but avoid lifting the lid too often.
6. About 10-15 minutes before serving, sprinkle the remaining mozzarella and Parmesan cheese on top. Cover and let the cheese melt.
7. Once done, garnish with chopped fresh parsley if desired, and serve hot!

What to Serve With

This rich, saucy casserole pairs beautifully with a crisp green salad tossed in Italian dressing—think romaine, cherry tomatoes, and crunchy croutons. For a true comfort food feast, add some warm garlic bread or soft dinner rolls for dipping into the cheesy sauce. Prefer something light to balance the meal? Steamed green beans or roasted broccoli make an excellent choice. To drink, try a sparkling Italian soda or a light-bodied red wine. Dessert can be kept simple with fresh fruit or a small dish of gelato. However you serve it, this casserole anchors a delightful family dinner spread.

Top Tips for Perfecting

– If you prefer, swap the ground beef for ground turkey, sausage, or a plant-based meat alternative for a healthier or vegetarian version.
– Don’t overcook the spaghetti—check for doneness after 3 hours, as some slow cookers run hotter than others.
– Using a high-quality marinara sauce elevates the entire dish; homemade is even better!
– Feel free to add chopped bell peppers or mushrooms to the meat mixture if you want more veggies.
– Sneak in some spinach or kale for extra nutrition without altering the flavor.
– For a creamier finish, stir in a dollop of ricotta or cream cheese before the final cheese topping.

Storing and Reheating Tips

To store leftovers, let the casserole cool to room temperature, then transfer it to an airtight container. It will stay fresh in the fridge for up to 4 days. For longer storage, portion into freezer-safe containers—the casserole freezes well for up to 2 months. To reheat, microwave individual portions until hot, adding a splash of water or sauce if needed to keep the pasta moist. If reheating from frozen, thaw overnight in the refrigerator and warm gently in the oven or microwave. Always cover with foil when reheating in the oven to prevent the cheese from drying out.

FAQs

Can I prepare this recipe ahead of time?

Yes! Brown the beef and assemble the casserole in your slow cooker insert the night before. Refrigerate overnight, then pop it into the slow cooker in the morning.

Can I use a different type of pasta?

Absolutely. Penne or rotini work well—just note the cooking time may vary slightly depending on the pasta shape and thickness.

Can I add vegetables to the casserole?

Definitely! Try diced bell peppers, mushrooms, zucchini, or spinach for added flavor and nutrition.

What size slow cooker works best?

A 6-quart slow cooker is ideal for this recipe. If using a smaller size, cut the ingredients proportionally to prevent overflow.

Is it possible to make this recipe vegetarian?

Yes, simply omit the beef or use a plant-based ground meat substitute, and feel free to load up on veggies for a hearty meatless meal.

Conclusion

Slow Cooker Spaghetti Casserole is proof that comfort food doesn’t have to be time-consuming or complicated. With just a little prep and a handful of pantry staples, you’ll end up with a hearty and delicious meal perfect for sharing with family and friends. Whether it’s a cozy Sunday dinner or a busy weeknight, this casserole will quickly find a place in your regular meal rotation. Don’t wait to experience just how easy—and satisfying—homemade pasta casserole can be. Ready, set, slow cook!

Slow Cooker Spaghetti Casserole

A comforting and easy-to-prepare spaghetti casserole made in a slow cooker, featuring layers of pasta, marinara, ground beef, and gooey cheese.

4.41 from 10 votes

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Prep Time 20 minutes mins

Cook Time 4 hours hrs

Total Time 4 hours hrs 20 minutes mins

Course Main

Cuisine Italian

Servings 6 servings

Equipment

• Slow Cooker
• Skillet

Ingredients

  

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Ingredients

• 1 lb Ground Beef
• 1 medium Onion, diced
• 2 cloves Garlic, minced
• 24 oz Marinara Sauce
• 14.5 oz Diced Tomatoes, drained
• 8 oz Tomato Sauce
• 1 tsp Dried Basil
• 1 tsp Dried Oregano
• 0.5 tsp Red Pepper Flakes (optional)
• to taste Salt and Pepper
• 8 oz Uncooked Spaghetti, broken in half
• 2 cups Shredded Mozzarella Cheese
• 0.5 cup Grated Parmesan Cheese
• 0.25 cup Chopped Fresh Parsley (optional, for garnish)

Instructions

 

• In a large skillet over medium heat, brown the ground beef with the diced onion until the meat is no longer pink and the onion is soft, about 6-8 minutes. Add minced garlic in the last minute. Drain off any excess fat.
• Transfer the cooked beef mixture to your slow cooker. Add the marinara sauce, diced tomatoes, tomato sauce, dried basil, dried oregano, and red pepper flakes. Stir to combine, then season with salt and pepper to taste.
• Break the uncooked spaghetti in half and stir it into the sauce mixture in the slow cooker, making sure the noodles are completely covered by sauce.
• Sprinkle 1 cup of mozzarella cheese and most of the Parmesan over the top, reserving some for the end.
• Cover and cook on low for 3-4 hours, or until the spaghetti is tender. Stir gently halfway through if desired, but avoid lifting the lid too often.
• About 10-15 minutes before serving, sprinkle the remaining mozzarella and Parmesan cheese on top. Cover and let the cheese melt.
• Once done, garnish with chopped fresh parsley if desired, and serve hot!

Notes

For a creamier finish, stir in a dollop of ricotta or cream cheese before the final cheese topping. This dish pairs well with a crisp green salad or garlic bread.

Keyword Comfort Food, Easy

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