Slow Cooker Mozzarella-Stuffed Meatball Recipe

There's absolutely nothing like a comforting Italian meal. Rich sauce, gooey cheese, and hearty meatballs can turn any day into an occasion to celebrate. The only problem is that these kinds of masterpieces tend to take some time. I remember going to my grandmother's on Sundays and watching her spend all day in the kitchen, making all of her Italian dishes from scratch. I've tried to recreate her recipes many times, but often end up covered in flour and tears, feeling completely overwhelmed. 

Fortunately, there are some shortcuts. Simple ingredients and your slow cooker can bring you a taste of Italy in no time. These mozzarella-stuffed meatballs and the homemade sauce taste just as good as Grandma's, while letting the slow cooker do the work. Not to mention the fact that taking a bite of these meatballs and discovering perfectly melted cheese inside is like unwrapping a present on Christmas morning. Go ahead. You deserve it!

Gather your ingredients

Start by gathering your ingredients. I used two pounds of ground turkey for these meatballs, because it's leaner than ground beef, and I don't think using turkey changes the taste. If you prefer ground beef or ground pork, they'll be delicious as well. You could also try a combination, like one pound of turkey and one pound of pork, to up the flavor. The secret to the cheesy center is string cheese — it doesn't get any easier than that!

Once you've assembled your ingredients, prepare your cookware. Preheat the broiler to high, line a large baking sheet with aluminum foil and spray with nonstick spray. We'll be making 32 good-sized meatballs, so use the biggest baking sheet you have. If you're not able to fit all of the meatballs, you can also broil them in phases. Finally, pull out your new bestie, the slow cooker, and spray it with nonstick spray. 

A full list of ingredients and step-by-step instructions can be found at the end of this article.

Season the breadcrumbs

Start by combining your dry ingredients. I like to use seasoned Italian breadcrumbs and then add more of my own spices. If you only have plain breadcrumbs on hand, use those and double the amount of dried spices you add. Combine the 3/4 cup Italian breadcrumbs with 1 teaspoon oregano, 1 teaspoon garlic salt, and 1 teaspoon garlic powder. Whisk with a fork to combine.

Add the wet ingredients

Next it's time to add the wet ingredients. First prepare your string cheese. Cut four cheese sticks in half crosswise, then cut each half into quarters, creating eight cubes per stick. You'll be left with a total of 32 cubes of cheese for your 32 meatballs.

Now wash your hands, because things are about to get messy. To your breadcrumb bowl, add the ground turkey and cracked egg. You could use a large wooden spoon to combine the ingredients, but using your hands is faster, and honestly, more efficient.

Massage with your hands

Combine the meatball ingredients with your hands. Massage until the ingredients are completely combined and all of the breadcrumbs are absorbed.

Add the string cheese

Using a large spoon, scoop out about two tablespoons of the ground turkey mixture. Press one of the mozzarella cubes into the mixture and form a ball with your hands, making sure the cheese is completely covered by the turkey. If any of the cheese is showing, it'll probably ooze out during cooking. No one wants to be the unlucky fellow to get the meatball that's lost its cheese.

Form the meatballs

Repeat the process with each cube of cheese until you've formed 32 meatballs. Make sure not to crowd them on the pan, because they could stick together as they cook. If you're not able to fit all 32 meatballs on the same pan, cook them in batches. Leave the extra meatballs on a clean plate and transfer them when you can. They cook very quickly, so this won't add a lot of time to the process.

Broil the meatballs

Once your broiler is hot, spray the tops of the meatballs with your cooking spray and place under the broiler, cooking for about three to four minutes. The meatballs should be browned on the top, but not completely cooked through. 

I love broiling the meatballs before tossing them into the slow cooker for two reasons. One, it helps them crisp up, so they won't become mushy and soggy in the slow cooker. Second, it cooks off some of the grease, so you can leave it on the aluminum foil as opposed to mixing it into your sauce. A little fat is good for the sauce, but too much will just leave it slimy and greasy.

Once you've broiled all of your meatballs, allow them to cool for a few minutes. We don't want them sticking together in the slow cooker, so a little cooling time will prevent that. Once they're no longer steaming, pour them into the prepared slow cooker. 

Mix the sauce

Once you've placed the meatballs in the slow cooker, it's time to make the easiest marinara sauce ever. Pour over the meatballs: Two cans crushed tomatoes, one can tomato paste, 1 tablespoon dried oregano, 1 tablespoon garlic salt, and 1 tablespoon garlic powder. Very gently start to stir the sauce together with a large spoon. Try to avoid mixing in the meatballs yet, because they could start to break apart. Just stir the sauce on top.

Normally you'd want to taste the sauce as you go, but because we have turkey that is not fully cooked already in there, we can't taste it just yet. If you really want to taste the sauce now, mix it together in a bowl before adding it to the slow cooker. If not, we can always add more seasoning at the end.

Combine and cook

Once you've mixed up your sauce, gently fold in the meatballs until they're completely coated with your tomato sauce. At this point a few meatballs may have a little cheese oozing out, but it will still stay in there. Cover your slow cooker and cook on low for about four hours. 

To check if the meatballs are done, cut into one. They turkey should be cooked through and no longer pink. The cheese will be melted and delicious. Sprinkle with fresh chopped basil and serve.

These meatballs are perfect over pasta, spaghetti squash, or any gluten-free pasta you like. We enjoyed them on whole wheat rolls for an easy take on a classic meatball hoagie. You can't go wrong!

Slow Cooker Mozzarella-Stuffed Meatball Recipe
5 from 1 ratings
These mozzarella-stuffed meatballs and the homemade sauce taste just as good as Grandma's, while letting the slow cooker do the work.
Prep Time
Cook Time
Total time: 4 hours, 30 minutes
  • 2 pounds grounds turkey
  • ¾ cup Italian seasoned breadcrumbs
  • 2 teaspoons dried oregano
  • 1 teaspoon garlic salt
  • 1 teaspoon garlic powder
  • 1 egg
  • 4 part-skim mozzarella cheese sticks
  • Non-stick spray
  • 2 (28-ounce) cans crushed tomatoes
  • 1 (6-ounce) can tomato paste
  • 1 tablespoon dried oregano
  • 1 tablespoon garlic salt
  • 1 tablespoon garlic powder
  • 2 tablespoons chopped fresh basil for garnish
  1. Preheat your broiler to high. Line a large baking sheet with aluminum foil and spray with nonstick spray. Spray the inside of your slow cooker with nonstick spray.
  2. To prepare the string cheese, cut each stick into eight cubes. Altogether, you'll have 32 cubes from your four cheese sticks.
  3. In a large bowl, combine the breadcrumbs, oregano, garlic salt, and garlic powder. Stir or whisk to combine.
  4. To the bowl, add two pounds of uncooked ground turkey and one egg. Massage with your hands until combined.
  5. Using a large spoon, scoop about two tablespoons of the ground turkey mixture into your hand and press one cube of string cheese into the center. Form a ball with your hands, making sure the cheese is completely covered by the ground turkey.
  6. Place the meatball on your prepared baking sheet. Repeat for all 32 meatballs.
  7. Once the meatballs are all prepared, place the baking sheet under the broiler for about 3-4 minutes. You want the meatballs to become slightly browned without cooking them all the way through.
  8. Remove the meatballs from the oven and allow them to cool for a couple of minutes before placing them into the slow cooker.
  9. Once the meatballs have been added to the slow cooker, pour in the crushed tomatoes, tomato paste, oregano, garlic salt, and garlic powder.
  10. Gently stir the tomato sauce without breaking apart the meatballs. Slowly fold the meatballs into the sauce. Cover the slow cooker and cook on low for four hours.
  11. When removing the meatballs, cut into one to ensure that the turkey is cooked and the cheese is melted. Sprinkle with fresh basil and enjoy!
Calories per Serving 87
Total Fat 2.9 g
Saturated Fat 1.1 g
Trans Fat 0.0 g
Cholesterol 28.6 mg
Total Carbohydrates 7.3 g
Dietary Fiber 1.4 g
Total Sugars 3.1 g
Sodium 212.1 mg
Protein 8.6 g
The information shown is Edamam’s estimate based on available ingredients and preparation. It should not be considered a substitute for a professional nutritionist’s advice.
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