Preheat oven to 450 degrees F (230 degrees C).
Line a baking sheet with parchment (if you wish) then drizzle some Olive Oil (2 tablespoon) over the top and spread out with your hand.
Lay the Eggplant (2) in a single layer — use two baking sheets if necessary. Season generously with Salt and Pepper (to taste). Flip the slices, season with salt and pepper. Drizzle more Olive Oil (2 tablespoon) over top.
Bake until golden brown, 15 to 20 minutes.
Remove pan from oven, flip slices, bake for 15 more minutes. Set aside.
Reduce oven temperature to 400 degrees F (200 degrees C).
Meanwhile, toss the Breadcrumbs (1 cup) with Parmigiano-Reggiano (1/3 cup), Olive Oil (2 tablespoon), and Salt and Pepper (to taste). Set aside.
Spoon a small amount of Tomato Sauce (to taste) into a circular gratin dish (about 9 inches in diameter) or a 9x9-inch or similar baking pan. Then add a thin scattering of Parmigiano, then a single layer of eggplant.
Repeat until all ingredients are used, ending with a little sauce and a sprinkling of Parmigiano. Top with breadcrumb mixture.
Bake until eggplant mixture is bubbly and top is golden, 25 minutes or so depending on size of pan and thickness of layers.
Remove from heat and allow to rest for 5 minutes before serving.