Prep your equipment: Preheat the oven to 400 degrees F. Line two baking sheets with parchment paper. Set them aside.
Cut the eggplant: Slice eggplant into ½-inch thick slices. Set them aside.
Set up your dredging station: Place two shallow dishes side by side. Crack and whisk eggs in the first one. Mix panko breadcrumbs, parmesan cheese, garlic powder, Italian seasoning, and black pepper in the second one.
Prep the eggplant: Dip each eggplant slice in eggs (letting the excess drip off) and then into the panko mixture, making sure that it is coated on all sides. You may have to gently push it down to ensure that the slices are fully coated.
Transfer to the baking sheet: Transfer onto the parchment-lined baking sheet in a single layer. Repeat with remaining eggplant slices. Lightly spray them with cooking spray.
Bake: Bake for 15 minutes; flip each eggplant round and rotate baking sheets, and bake for another 10-12 minutes or until lightly browned on top and soft to the touch.
Cool: Set it aside to cool for 5-8 minutes. Do not turn the oven off.
Assemble the eggplant parmesan: In a large casserole dish (I used a 9x13 inch baking dish), spread ½ cup tomato sauce at the bottom. Arrange baked crispy eggplant slices on top in an even layer. Spread it with 1 cup of tomato sauce, half of the shredded mozzarella cheese, half of the parmesan cheese, and half of the fresh basil.
Add additional layers: Add another layer of baked eggplant and spread it with the remaining tomato sauce, mozzarella cheese, and parmesan cheese.
Bake: Bake for 20-25 minutes or until the cheese has fully melted and the top has turned lightly golden brown.
Cool, garnish, and serve: Let it cool on a wire rack. Garnish it with fresh oregano and the remaining basil. If desired, sprinkle with a pinch of red pepper flakes and more parmesan cheese when serving.