Press the block of tofu in a tofu press to remove the liquid, or place it between two folded pieces of kitchen paper towel on a cutting board with a heavy pan on top. Don't skip this step! Pressing the tofu to remove the liquid helps the tofu become crispy when cooked.
While the tofu is draining for 7-10 minutes, add the soy sauce, maple syrup, garlic powder and sesame oil to a bowl and whisk them together.
Add the cornstarch to a separate small bowl.
When the tofu has been pressed, slice it into 1 to 1 1/2-inch cubes and add the tofu cubes to the bowl with the marinade. Toss the tofu in the marinade.
Remove the tofu from the marinade and toss it in the cornstarch to coat. Shake off any excess cornstarch.
Spray the basket of the air fryer with non-stick baking spray, olive oil spray, or something similar. This will prevent the tofu from sticking.
Place the cubes of tofu in the basket of the air fryer in a single layer, spacing them apart.
Air fry at 400 degrees Fahrenheit (200 degrees Celsius) for 5 minutes. Shake the basket to turn the tofu after 5 minutes and air fry for another 4-6 minutes until the tofu cubes are golden brown and crispy.
Serve with sesame seeds and sliced green onions, over salads, noodles, or rice with veggies.