Flavorful Spinach Meatballs with Gooey Mozzarella

Bite into super-soft meatballs loaded up with chopped spinach and fresh garlic, and you'll find gooey mozzarella right in the center that gets all stretchy and fun. The outside gets a deep golden brown while the inside stays cheesy and melty, so every bite is a mix of cozy comfort and a little fancy twist. These show-stopper meatballs can go from a chill family meal to a more dressed up get-together, and you don’t need any special skills to pull them off—they look impressive but are actually really laid back to make.

Just last month, my sister and her crew came over for Sunday night and I whipped up these meatballs. When my little nephew sliced open his meatball and saw the oozing cheese, his jaw dropped. "Is there a cheesy surprise in there?" he shouted before inhaling two more. There’s something about juicy meat wrapped up around melty cheese that makes even picky kids grin from ear to ear.

Tasty Key Ingredients

• Olive Oil: Gets the outside brown and crispy during the first quick fry. If you use extra virgin, you'll get a faint peppery bite along with a nice golden color.
• Mozzarella Cheese: Packs the gooey center. Go with dry mozzarella because it melts just right and doesn’t get soupy.
• Salt and Pepper: Just the basics for making sure everything pops with flavor. Don’t skip these or the taste falls flat.
• Parmesan Cheese: Helps bring out a savory, rich bite. Shredding it yourself works way better than the pre-grated stuff, which can clump.
• Egg: Holds the whole mix together. You just need a big egg—it's the right amount to keep things from falling apart but not too wet.
• Breadcrumbs: Soaks up juices and makes a soft bite. Panko gives them an airy texture, while old-school breadcrumbs keep them a bit more compact.
• Garlic: Smells amazing and flavors the whole batch. Use real, fresh garlic for the best punch—skip the pre-chopped jars.
• Fresh Spinach: Adds color and a little earthiness. Chop super fine to make sure it’s evenly mixed in and not clumpy.
• Ground Beef: The main event and brings the rich meaty taste. 85% lean is great, not too dry, not too greasy.

Simple How-To Guide

Get Set Up

First, switch the oven on to 375°F. Round up all your ingredients so you're not scrambling later. Put parchment paper on a baking tray—less mess, less sticking.

Mix It Up

In a big bowl, toss in ground beef, chopped spinach, breadcrumbs, garlic, egg, parmesan, salt, and pepper. Mix gently with your hands until it looks even. Don’t squeeze it too much or your meatballs turn out tough instead of soft.

Prep the Cheese

Chop mozzarella into about half-inch cubes—aim for a dozen or so, all kind of the same size. If you're using a block or string cheese, as long as they're close in size, you're good.

Shape Meatballs

Grab about two spoons’ worth of the mix and flatten it out in your hand. Pop a cube of mozzarella in the middle, then close the meat around it, making sure it’s sealed up tight so no cheese sneaks out later. Roll it gently to even it out.

Brown Them

Put a big pan on medium-high and let the olive oil heat up until it shimmers. Place the meatballs in so there’s a little space between each. Let them brown for about a minute on every side, turning them to get lots of color but not cooking all the way through yet.

Bake Them

Scoot the browned meatballs onto your lined tray, then put them in the oven. Give them 10-12 minutes. Once the inside is at 165°F, they’re completely done and the cheese is perfectly stretchy.

Let Them Rest

Pull the tray out and leave the meatballs alone for two to three minutes. This helps the juices soak back in and keeps the cheese from burning your mouth. Top ’em with spoonfuls of marinara and fresh chopped herbs if you’re feeling fancy.

Save

My grandma always said to go easy when mixing meatballs. She pointed out how the heat from your hands can make the fat melt and the meat get chewy if you’re too rough. Back when I first tried cheese-stuffing these, I made the mistake of squishing the mix trying to make perfect balls. They came out bouncy—not what I wanted. Following her advice, I now just mix enough to combine and try not to fuss with the meat after. That’s the secret to meatballs you can actually bite through without a fight.

Serving Ideas

You can team these cheesy meatballs up with all sorts of sides. Pile them onto pasta with a bright marinara and lots of basil for hearty family meals. Feel like showing off? Layer them over super-creamy polenta and top with roasted cherry tomatoes for a dinner that looks awesome. For a chilled-out party, just toss them on a tray with toothpicks, crusty bread, and a bowl of warm sauce for dipping.

Fun Ways to Switch Things Up

This base can be tweaked so many ways and it’ll still be a hit. Craving Mediterranean? Use lamb and feta for the centers, then stir in a little chopped mint. If you like lighter flavors, try ground chicken or turkey with fontina stuffed inside. Want another level of flavor? Throw in chopped sun-dried tomato, fresh basil, and slices of provolone cheese for a punchy Italian spin with cheesy surprises in every bite.

How to Store and Keep Fresh

Pop extra meatballs in a sealed container and keep in the fridge up to three days—they’ll stay safe and taste just as good. When it’s time to heat them up, cover with foil and warm in a 350°F oven so they don’t dry out. To freeze, lay cooled meatballs on a tray until hard, then put them in freezer bags. They’ll stay tasty for up to three months.

Save

I’ve lost count of how many times I’ve made these for my family and friends—they’re always a favorite. They hit just the right note between looking like you put in real effort and actually being totally do-able. Everyone loves that moment when they hit that stringy, melted cheese pocket inside. Serve with pasta for something filling during the week, or put out a big platter for a party. Either way, these meatballs are pure happiness and always disappear fast.

Recipe FAQs

→ Can I prepare these meatballs in advance?

Of course! Roll the meatballs and keep them uncooked in your fridge for up to a day. Or, fully cook them and refrigerate for three days, making reheating quick. You can freeze cooked meatballs for three months too—just reheat in the oven at 350°F for 10-15 minutes or warm them in sauce.

→ How do I keep the mozzarella from spilling out?

Seal the cheese tightly with the meat mixture, ensuring no cracks or thin spots. Pop the meatballs into the fridge for 15-30 minutes to firm them up before cooking. Stick to cheese cubes, not shredded, since they melt slower while the meat cooks.

→ What are some serving options for these meatballs?

They're so flexible! Pair with pasta and marinara to keep it classic, or try zucchini noodles for a low-carb spin. Turn them into meatball subs, serve on creamy polenta, or enjoy with roasted veggies. You could even pop toothpicks in and serve them as a party snack with a dip.

→ Can I substitute fresh spinach with frozen spinach?

Totally! Frozen spinach works great here. Just thaw it out completely and squeeze it to remove extra water. Since frozen spinach is already condensed, use about 1/4 cup of it to replace every 1/2 cup of fresh spinach.

→ How can I make this dish without gluten?

Swap the breadcrumbs for gluten-free alternatives, like ground-up crackers, gluten-free breadcrumbs, or even almond flour. Quinoa or rice can also replace breadcrumbs—the texture might shift a bit, but it'll still have that cheesy goodness inside.