Coat a baking sheet with cooking spray. In a medium bowl, toss the squash with the olive oil. In another bowl, combine the bread crumbs, parmesan cheese, dried oregano and a pinch of black pepper. Dip each squash round into the parmesan mixture, coating it evenly on both sides, pressing the coating on so it sticks. Place the squash in a single layer on the prepared baking sheet. Bake the rounds until browned and crisp, 25 to 30 minutes. Serve immediately.