Arrange eggplant rounds on a baking sheet;lightly coat with olive oil.
Bake eggplant rounds in preheated oven until hot, about 5 minutes.
Flip the eggplant rounds; top with Parmesan cheese in an even layer to cover. Return eggplant to oven and bake until the cheese is melted, about 5 minutes.
Drop a dollop of tomato sauce into the center of each eggplant round; top with Cheddar cheese.
Bake until Cheddar cheese is bubbling, about 5 minutes more. Season with salt and pepper to serve.