01 -
Preheat your oven to 190°C and position the rack in the middle.
02 -
Lightly grease a 23x33 cm casserole dish (e.g., with cooking spray). Arrange the frozen meatballs in a single layer. If using thawed cooked meatballs, proceed to the next step.
03 -
Bake the meatballs for 20 minutes, then remove the casserole dish from the oven.
04 -
Pour marinara sauce over the meatballs and stir to coat evenly. Spread in a single layer and sprinkle the shredded mozzarella cheese on top.
05 -
Return the casserole dish to the oven and bake for an additional 15-20 minutes, or until the dish is hot and bubbly. Ensure the meatballs reach an internal temperature of 71°C. For a browned cheese topping, broil for a few minutes if desired.