Squeeze the tofu block, by placing it in a clean kitchen towel and then you will want to place something heavy on top of it. It can be a skillet with a weight placed in it, like several canned food items or like shown, a cutting board. You will not need to push down on it, just allow the weight to squeeze the water out. With extra firm tofu, it has less water in it already than a soft tofu.  Allow this to sit for 15 minutes or so. 

Once the moisture is squeezed out and then cut into 1 inch chunks. 

In a bowl, combine the marinade ingredients: the soy sauce, avocado oil, sesame oil, vinegar, garlic powder and ground ginger. 

Pour this over the tofu blocks and allow to marinate for 15 minutes. 

Sprinkle cornstarch over the cubes, carefully flipping them on their sides to continue to coat them. 

Preheat your air fryer to 380 and then in a single layer, place your tofu in the basket. Cook for 10 minutes, flipping occasionally and carefully with tongs, till cooked to the desired crispiness.