Cut the tofu block into five slabs; lay them flat and place them between kitchen towels or paper towels. Press on them gently to drain for just a minute or two - you want the tofu to be quite moist inside because the air fryer will dry it out rapidly. Removing too much moisture leads to tough overcooked tofu.

After a bit of water has drained out, cut the tofu into 3/4" cubes.

Place the tofu cubes in a bowl and pour the soy sauce over, and sprinkle with salt and pepper. Stir very gently so the tofu absorbs the seasoning, without breaking. Sprinkle the cornstarch over and stir or toss the tofu until it's coated.

Spritz the air fryer basket with oil. Dump the tofu in, moving pieces around as needed so the tofu is in one layer. Spritz the top of the tofu with oil.

Air fry the tofu cubes at 400 degrees F for about 10 minutes or until it is crispy and golden brown on the outside, shaking and tossing about halfway through.

Serve hot or at room temperature.