Prepare the slow cooker: Spray the inside of your slow cooker with non-stick spray or line it with foil for easy cleanup. This helps prevent the meatloaf from sticking and makes serving simpler.
Mix the meatloaf: In a large mixing bowl, combine the ground beef, French onion soup mix, breadcrumbs, eggs, milk, garlic powder, and shredded mozzarella. Mix gently by hand or with a spoon until everything is evenly blended, being careful not to overmix, which can make the meatloaf dense.
Shape and place: Form the mixture into a loaf shape and place it in the prepared slow cooker, centered for even cooking.
Add topping: Spread ketchup evenly over the top of the loaf. This gives it a sweet, tangy glaze as it cooks.
Cook: Cover and cook on low for 6–7 hours or high for 3–4 hours, until the meatloaf is fully cooked and reaches an internal temperature of 160°F (71°C). The slow cooker locks in moisture, ensuring a tender, flavorful result every time.
Rest and serve: Once done, let the meatloaf rest for about 5 minutes before slicing. Garnish with a sprinkle of fresh parsley if desired. Serve warm with mashed potatoes, steamed vegetables, or a crisp salad for a complete meal.
