Preheat the oven to 400 degrees F (200 degrees C). Coat a shallow baking dish with cooking spray.
Place tomato slices close together in the prepared baking dish. Sprinkle with cheese, bread crumbs, garlic, parsley, salt, pepper, and oregano. Drizzle with olive oil.
Bake for 20 minutes in the preheated oven, or until cheese is lightly toasted.