Put a cooling rack on a cookie sheet and lay the eggplant slices out on the rack.
Generously salt both sides of the eggplant slices. Let sit for 30 – 60 minutes, then rinse and pat dry. (This helps release the bitterness of the eggplant and makes it less soggy when cooked.)
Dip the eggplant slices in the egg and then in the italian breadcrumbs to coat and place them back on the cooling rack.
Coat the bottom of a heavy frying pan with oil and put on medium heat.
In batches, cook the eggplant slices until browned on both sides.
Preheat oven to 350 degrees.
Spread some spaghetti sauce on the bottom of a 9×13 pan.
Build the eggplant towers in the pan. Each tower will have 3 eggplant slices each topped with a slice of mozzarella, sprinkle of basil leaves, and a spoonful of spaghetti sauce.
Sprinkle the parmesan cheese on top of the towers and top each one with a basil leaf.