Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper or a silicone baking mat.
Cut the pressed tofu into 1-inch cubes (or bite-sized pieces). Pat any remaining moisture off with a towel if needed.
Place the tofu cubes in a medium bowl and add the tamari. Gently toss with a spatula to coat evenly.
Sprinkle the cornstarch evenly over the tofu, then add the nutritional yeast, onion powder, and garlic powder. Gently toss until the cubes are evenly coated and the cornstarch is not clumped.
Arrange the coated tofu cubes in a single layer on the prepared baking sheet, spaced apart to allow airflow.
Bake for 20 minutes, then carefully flip each cube and bake for an additional 18–20 minutes until golden and crispy.
Remove from the oven and let cool slightly before serving.