Preheat your oven to 375°F (190°C).

Slice your zucchinis into rounds and dice your onion and garlic.

Heat some olive oil in a pan over medium heat and sauté the onion and garlic until soft and fragrant.

Add the sliced zucchinis to the pan and cook until they're just tender, about 5-7 minutes.

Transfer the cooked zucchinis, onion, and garlic to a baking dish and sprinkle with shredded mozzarella and grated Parmesan cheese.

In a small bowl, mix together breadcrumbs, Italian seasoning, salt, and pepper. Sprinkle this mixture over the top of the cheese.

Bake in the preheated oven for 20-25 minutes, or until the cheese is bubbly and golden brown.

Remove from the oven, let it cool for a few minutes, and then dig in!