Lay the sliced eggplant on a baking sheet and sprinkle both sides with 1 teaspoon salt. Let sit for 20–30 minutes to draw out excess moisture, then pat dry.
Whisk flour with a pinch of salt in one bowl. Mix plant milk and apple cider vinegar in a second bowl. Combine panko, ground cashews, nutritional yeast, oregano, garlic powder, salt, and pepper in a third bowl.
Preheat oven to 425°F (220°C). Dredge each eggplant in flour, dip in plant milk mixture, then press into breadcrumb mix. Arrange on a parchment-lined sheet, brush with olive oil, and bake 20–25 minutes, flipping once, until golden.
Reduce oven to 375°F (190°C). Spread a thin layer of marinara in a baking dish, layer eggplant slices, spoon sauce, and sprinkle vegan cheese. Repeat for 2–3 layers, finishing with sauce and cheese.
Bake assembled dish at 375°F (190°C) for 20–25 minutes until bubbly and the top is golden. Let rest 10 minutes before serving.