Preheat oven to 200°F. Line a baking sheet with paper towels.
Warm 2 Tbsp. olive oil in a large skillet over medium heat. Whisk eggs, salt, pepper, garlic powder and parsley in a medium bowl. Working in batches, dip eggplant slices into egg mixture. Shake off excess and place slices in a single layer in skillet. Cook until browned, 1 to 2 minutes per side. Transfer slices to baking sheet; place in oven to keep warm. Repeat with remaining eggplant. If burned bits accumulate, wipe out skillet with a paper towel between batches and add remaining olive oil.
Warm marinara sauce in a small pan over low heat. Spoon 1 Tbsp. sauce onto each of 4 plates; top each with an eggplant slice. Spoon more sauce over, sprinkle with Parmesan and add another eggplant slice. Repeat layers until no eggplant remains. Top each stack with 2 Tbsp. sauce, sprinkle with more Parmesan and serve.