Preheat the oven to 200°C (400°F). Gather your ingredients and prepare your workspace.

Heat two tablespoons of olive oil in a medium skillet over medium heat. Add finely diced onion and minced garlic, sauté for 5-7 minutes until soft and fragrant. Let cool.

In a large mixing bowl, combine ground chicken with the cooled onion and garlic. Fold in seasoned breadcrumbs, milk, grated Parmesan, egg, chopped parsley, Italian seasoning, and salt. Mix until just combined.

On a baking sheet lined with parchment paper, shape two-thirds of the chicken mixture into a rectangle. Create a well in the center and add shredded mozzarella, topping it with the remaining mixture.

Spread marinara sauce over the top and bake for 45 minutes until bubbling and browning.

Mix panko breadcrumbs, grated Parmesan, melted butter, and chopped parsley. After initial baking, sprinkle on top with more mozzarella and return to the oven for 15-20 minutes until golden brown.

Let the meatloaf rest for 10 minutes before slicing to redistribute juices.