Wrap the tofu in paper towels or a clean tea towel. Place a heavy object, like a cutting board with a cast iron skillet on top, to press out the moisture for about 15-20 minutes.

Dice the pressed tofu into 1-inch cubes and transfer them to a bowl. Season with salt and black pepper, then add cornstarch, garlic powder, and onion powder. Toss gently to ensure each piece is evenly coated.

Heat oil in a large non-stick skillet over medium-high heat. Once the oil is hot, add the tofu cubes in a single layer. Allow them to cook undisturbed for 2-5 minutes on one side until golden, then carefully flip each cube and fry until all sides are golden and crisp, about another 2-5 minutes per side.