Preheat the oven to 350f.
Mix together the ricotta, parmesan, eggs and some salt and pepper in a bowl.
Spread a layer of the marinara sauce into the base of a baking dish then top with a layer of the courgettes.
Spread over around one third of the ricotta mixture followed by one cup of the mozzarella.
Spread another layer of marinara sauce, courgette, ricotta and mozzarella then repeat one more time for the final layer.
Finish with a layer of courgettes and sprinkle over some extra parmesan – or vegetarian alternative.
Season with some cracked black pepper then place into the oven to bake for around 30 minutes until the cheese is melted and the courgettes cooked fully.
Remove from the oven and allow to stand for 5-10 minutes before serving with freshly baked crusty bread.