Preheat the oven to 400F. Slice the eggplant into ¼-inch thick slices. Prepare a baking sheet with olive oil.
Set up three shallow bowls for breading the eggplant. In the first bowl, place the 1/2 cup flour, 1/4 teaspoon salt and 1/4 teaspoon black pepper. In the second bowl, crack in the egg and add 3 tablespoons water. Scramble the egg and water together. In the third bowl, combine the 2 cups panko, Italian seasoning, garlic powder, 1/2 teaspoon salt and 1/4 teaspoon black pepper.
Prepare the eggplant by dredging each slice in the flour, then the egg, then the breadcrumbs, making sure to fully coat in each step. Place on a baking sheet and repeat until all eggplant is coated.
Bake in the oven for 15 minutes, then flip the slices and bake for another 15 minutes.
Remove the eggplant from the oven and top each slice with a dollop of tomato sauce and a thin slice of mozzarella. Put back into oven for 5-10 minutes until the cheese is melted.
Remove from the oven and create eggplant stacks by stacking 3-4 slices up at a time. Serve with pasta, bread and/or a side salad!