Press tofu until most of the liquid is removed. If using a tofu press, press tofu to half its original width and let it drain for at least 15 minutes.
Cut tofu into 1/2″ – 1″ cubes and toss tofu in cornstarch (optional).
Place tofu on a baking sheet with a silicone liner and spray with cooking spray to coat. Bake in preheated oven for 20-30 minutes or until cubes are as crisp as desired.
Store any leftovers in airtight container in the refrigerator.