Preheat and prep. Heat your oven to 350°F (175°C). Line a sheet pan with parchment or lightly oil a loaf pan. A free-form loaf on a sheet pan browns better; a loaf pan is neater. Your choice.

Soak the breadcrumbs. In a bowl, combine 1 cup breadcrumbs and 3/4 cup milk. Let sit 5 minutes until soft. This “panade” keeps the loaf tender and moist.

Sauté aromatics. Warm 1 tablespoon olive oil in a skillet over medium heat. Cook 1 finely minced onion with a pinch of salt for 5–7 minutes until translucent. Add 3 cloves minced garlic and cook 30 seconds. Let cool to lukewarm so it doesn’t scramble the eggs.

Make the glaze. In a small bowl, mix 1/4 cup ketchup, 1 tablespoon tomato paste, and 2 teaspoons balsamic vinegar. Add a pinch of oregano and black pepper. Set aside.

Combine the meat mixture. In a large bowl, add 1.25 lb ground beef and 0.75 lb Italian sausage. Add the soaked breadcrumbs, cooled onion-garlic mixture, 2 beaten eggs, 1/2 cup grated Parmesan, 2 tablespoons chopped parsley, 1 tablespoon chopped basil, 1 teaspoon dried oregano, 1 teaspoon kosher salt, and 1/2 teaspoon black pepper. If you like heat, add a pinch of red pepper flakes and 1/4 teaspoon crushed fennel seeds.

Fold in mozzarella. Add 1 cup low-moisture mozzarella cut into small 1/4-inch cubes. Gently fold it through so the cubes are distributed but not crushed. This gives you melty pockets rather than a single gooey center.

Mix gently. Use your hands to combine just until everything comes together. Avoid overmixing; it can make the loaf dense. If the mixture feels too wet, sprinkle in a bit more breadcrumbs. If too dry, add a splash of milk.

Shape the loaf. Transfer to your prepared pan. Shape into a firm, even loaf about 9 inches long. Smooth cracks so it holds together and bakes evenly.

Top with glaze. Spread the tomato glaze over the top and sides for color and flavor. Reserve a little to brush on halfway through if you like a thicker coating.

Bake. Bake for 50–65 minutes, until an instant-read thermometer in the center reads 160°F (71°C). If the glaze darkens too fast, tent loosely with foil.

Rest. Let the meatloaf rest for 10–15 minutes. This step matters. Resting keeps the juices inside and makes slicing cleaner.

Slice and serve. Cut into thick slices. Finish with a sprinkle of fresh basil or parsley and extra Parmesan. Pair with roasted broccoli, garlicky green beans, or a simple arugula salad with lemon.