Put a baking sheet on the bottom rack of the oven and preheat to 500 degrees F. Position a wire rack over a second baking sheet and set aside.
Mix the panko and Parmesan in a shallow bowl and season with salt and pepper. Season both sides of the eggplant with salt and pepper. Dip only one side of the eggplant slices first in the beaten egg, then in the breadcrumb mixture to coat. Transfer to the wire rack.
Carefully remove the baking sheet from the oven and reduce the oven temperature to 350 degrees F. Pour the oil directly onto the hot baking sheet. Working quickly, place the eggplant slices panko-side down onto the oiled baking sheet. Dollop sauce directly on the center of each eggplant slice, then top with a nice slice of mozzarella (drape it over the sides of the eggplant for legendary crispy bits). Put immediately back on the bottom rack of the oven and bake until the bottoms are golden brown and the tops are melted and bubbly, 15 to 20 minutes.
Garnish each eggplant medallion with a basil leaf. Serve immediately, either individually or in a giant stack.