Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with olive oil.
In a large bowl, combine the sliced zucchinis, cherry tomatoes, garlic, oregano, salt, and pepper. Toss to coat the vegetables evenly.
In a separate bowl, whisk together the eggs and milk until well combined.
Add the egg mixture to the zucchini mixture and stir until everything is coated.
Spread the vegetable mixture evenly in the prepared baking dish.
In a small bowl, mix the breadcrumbs, mozzarella cheese, and Parmesan cheese. Sprinkle this mixture evenly over the top of the zucchini bake.
Bake in the preheated oven for 25-30 minutes, or until the top is golden brown and the zucchini is tender.
Remove from the oven and let it cool for a few minutes before serving. Garnish with fresh basil leaves if desired.