Slice eggplant into ¼‑inch rounds and sprinkle both sides with salt. Place in a colander to draw out moisture, then pat completely dry between paper towels.

Prepare three bowls: flour mixed with onion powder and paprika; whisked eggs (with optional mustard and cream); breadcrumbs combined with Parmesan and parsley.

Dredge eggplant in flour, dip in egg mixture, and coat in breadcrumb mix. Press firmly so breading adheres.

Heat oil in skillet to around 350 °F; fry eggplant slices in batches until golden on both sides (~2–3 minutes per side). Drain on a wire rack over paper towels.

Spread about 1/3 cup marinara in a 9×13″ baking dish. Arrange a third of the slices in a single layer. Spoon more sauce over and sprinkle with 1/3 each of mozzarella and Parmesan.

Repeat layers two more times: eggplant, sauce, cheeses.

Bake uncovered at 375 °F for 25–30 minutes until bubbly. Optional: broil briefly to brown the top (watch carefully).

Remove, let rest ~10 minutes before serving. Garnish with fresh basil if desired.