Start by removing the tofu from its package and patting it dry with a clean kitchen towel.
In a medium-sized bowl with a lid, break the tofu into chunks that are about 1 ½ to 2 inches in size using your hands.
Add the tamari, apple cider vinegar, onion powder, and salt to the tofu, and gently mix to ensure all pieces are well coated with the seasonings.
Sprinkle the cornstarch and nutritional yeast over the tofu, then cover the bowl with the lid and shake it to coat the tofu evenly.
If you don't have a bowl with a lid, you can place the cornstarch and nutritional yeast in a freezer bag, add the tofu chunks, and shake to coat.
Arrange the coated tofu pieces in a single layer in the air fryer basket, making sure to include any leftover batter and small bits.
Air fry the tofu at 400 degrees Fahrenheit for 11 to 13 minutes, shaking the basket and spraying with oil halfway through for even cooking.
Continue to air fry, stopping once or twice more to spray and shake for optimal browning.
The tofu nuggets are done when they are golden and crispy; test one to ensure it meets your desired crispiness.
Remove the tofu from the air fryer, making sure to collect any crispy bits that may have fallen through the grate, as they are delicious.
Serve the nuggets with your favorite dipping sauce if desired.
