Gather the ingredients. Preheat the oven to 375F degrees. Dice onion small.
In a mixing bowl place all the ingredients, including 4 tablespoons of ketchup. Mix to combine. Divide the meat into two parts.
In an oven-safe dish place one half of the meat. Press tightly to form the meat layer.
Layer the mozzarella slices, slightly overlapping and keeping away from the edges.
Place the second meat part to form the layer on top. Using two tablespoons of ketchup spread the sauce all over on top to cover the meat layer.
Bake for 45 minutes. Cool for 5-10 minutes before slicing.
Notes
To make this dish healthy, use ketchup without sugar or with reduced sugar.Don’t overmix to keep the meatloaf texture soft and tender.The internal temperature of the cooked meatloaf should be 165 degrees.