1. Peel eggplant, slice off both ends thinly. Slice 1/2" thick. Do the same for the zucchini.
2. Beat eggs in a bowl until yolks and whites mix. Pour into shallow dish. Spread seasoned bread crumbs in a plate.
3. Dip eggplant slices in egg, then in bread crumbs until covered. Place breaded slices on cookie sheet. Place zucchini slices (breaded or not) between eggplant slices.
4. Place a dab of butter on each slice; broil 5 minutes or until golden brown. Turn slices over; add another dab of butter to each side, and broil again.
5. Preheat oven to 350°F.
6. Grate 1 lb mozzarella cheese into shredded strips. In a glass casserole dish, layer:
1/2 of the eggplant/zucchini, fitted together
1/2 of the marinara sauce
1/2 of the cheese
Repeat layer, ending with cheese on top.
7. Bake for 45 minutes to 1 hour (until cheese melts and is browned slightly on edges).