Add the oil to a nonstick skillet over medium heat and allow it to become very hot but not smoking.
While the oil heats, add the cornstarch, nutritional yeast, garlic powder, salt, and onion powder to a zip bag or storage container with a lid. Add the tofu and give it a few shakes.
Add the tofu to the skillet. Fry on the first side until it is golden brown and completely released from the pan, at least 20 minutes.
Flip the tofu carefully and fry on the second side for at least 15 minutes or until golden brown.
Once the tofu is fried to your preference, remove the tofu from the oil, keeping the oil in the pan. Life the tofu out with a slotted spoon or tongs and transfer to a plate lined with paper towels or a draining rack over a baking sheet. Sprinkle with salt.