Step 1: Preheat your oven to 375°F (190°C). Line a large baking sheet with parchment paper to ensure easy cleanup and prevent sticking.
Step 2: In a spacious mixing bowl, gently combine the ground beef, ground turkey, breadcrumbs, grated Parmesan cheese, milk, egg, minced garlic, dried oregano, dried basil, and a generous seasoning of salt and pepper. Use your hands to mix until the ingredients are just incorporated. Be careful not to overmix, as this can result in tough meatloaf bites.
Step 3: Take about 1 ½ inches of the prepared meat mixture and roll it into a smooth, even ball between your palms. Place each formed meatball onto the lined baking sheet. You should aim to make approximately 12-14 meatballs.
Step 4: Using your thumb or a small spoon, create a shallow indentation in the center of each meatball. Be mindful not to press all the way through the bottom. Fill each well with approximately one tablespoon of shredded mozzarella cheese. Carefully mold the meat mixture around the cheese, sealing it completely to prevent any cheese from escaping during baking.
Step 5: Arrange the stuffed meatballs on the baking sheet, ensuring there is a little space between each one to allow for even cooking. Bake in the preheated oven for 18-20 minutes, or until the meat is thoroughly cooked through and the mozzarella is gloriously melted and bubbling. For optimal food safety, ground meat should reach an internal temperature of 160°F (71°C).
Step 6: While the meatloaf bites are baking, gently warm your marinara sauce. Pour the sauce into a small saucepan and heat over medium heat, stirring occasionally, until it reaches a gentle simmer and is hot throughout, typically 5-7 minutes.
Step 7: Once the cheesy meatloaf bites are removed from the oven, you can either drizzle them generously with the warm marinara sauce or serve the sauce on the side for dipping. Serve immediately and savor every bite of this cheesy, savory goodness!