Preheat oven to 300°F (150°C) and line a large baking sheet with parchment paper.
Place the air-popped popcorn in a large mixing bowl.
In a small bowl, whisk the liquid egg whites until slightly frothy.
Drizzle the egg whites over the popcorn and toss thoroughly until every kernel is lightly coated.
Sprinkle the nutritional yeast, garlic powder, oregano, thyme, salt, and pepper over the popcorn, tossing to distribute the spices.
Add the finely grated parmesan cheese and hemp hearts, giving it one final toss to ensure the toppings adhere to the egg white coating.
Spread the popcorn in a single layer on the prepared baking sheet.
Bake for 8-10 minutes, or until the popcorn is dry and the cheese is fragrant and golden.
Remove from the oven and let cool for 2 minutes to allow the coating to fully crisp up before serving.