Drain the tofu, then wrap it in a clean tea towel. Place it between two flat surfaces with a heavy object (like a cast-iron skillet) on top to help remove excess water, which helps the tofu absorb the marinade better.
In a large container, whisk together the tofu marinade ingredients, ensuring the container is spacious enough to accommodate the tofu. Allow the tofu to marinate for a few minutes while you prep the cornstarch coating.
Once marinated, transfer each tofu cube into a separate container or freezer bag with the cornstarch, draining the excess marinade. Toss the tofu until each piece is uniformly coated, which will help it crisp evenly in the oven.
Arrange the tofu cubes on a lined baking sheet and bake at 400F for 25-30 minutes. To ensure even cooking, turn the tofu halfway through. The end result should be golden-brown, crispy tofu cubes!
While the tofu is in the oven, pour the remaining marinade into a frying pan and heat the mixture over medium until it thickens. Toss the baked cubes in the reduced marinade, then serve the tofu with rice, green onions, and toasted sesame seeds.