Line a large rimmed baking sheet with parchment paper and set aside.
Prepare the Tofu:
Squeeze out the water from the tofu by placing it between two kitchen towels (or paper towels) and pressing on it gently with your hands or a cast iron pan.
Slice the tofu into cubes, arrange them into one layer on a kitchen towel (or paper towels) and place something heavy on top, like a cast iron pan to squeeze out as much water as possible. Let stand like this for 20-30 minutes.
Transfer the pressed tofu cubes to a medium bowl and drizzle with the olive oil and soy sauce. Toss to combine.
In a bowl combine cornstarch, garlic powder, onion powder, and cayenne pepper.
Sprinkle the mix over the tofu, and toss the tofu until it is evenly and well coated.
Arrange the tofu in an even layer onto the prepared baking sheet. Bake for 25 to 30 minutes, tossing the tofu halfway through baking. Bake until the tofu is deeply golden on the edges and crispy.