2. In a large mixing bowl, toss the summer squash with half of the oregano and season generously with salt and pepper. Transfer the seasoned squash to a large baking dish and cover with the sliced tomatoes.
3. In a small bowl, combine the remaining oregano, bread crumbs, Parmesan cheese, garlic, salt and pepper. Sprinkle the bread crumb mixture over the tomatoes and drizzle with olive oil.
(This can be prepared in advance and stored in the refrigerator for up to 1 day.)
4. Bake until golden brown and bubbly around the edges of the dish, about 45 minutes. Let stand for 5 minutes before serving.