Make the sauce: In a small bowl, whisk together the sake, mirin, tamari, brown sugar, 1 tablespoon cornstarch, fresh garlic, and fresh ginger. Set aside.

Use a kitchen towel or paper towels to pat the pressed and cubed tofu dry. Place the tofu pieces in a large bowl and set aside.

In a small bowl, combine the cornstarch, garlic powder, and onion powder. Sprinkle over the tofu and gently toss to coat all the pieces.

Set a large skillet or wok over medium-high heat and add the vegetable oil. When the oil is hot, add the tofu in a single layer. You may need to work in batches to avoid overcrowding. Cook the tofu for 10 minutes, gently turning occasionally until golden brown and crisp on all sides.

Reduce the heat to low and pour the teriyaki sauce over the cooked tofu. Toss gently to coat each piece evenly. Cook for an additional 2 minutes, allowing the tofu to absorb the sauce.

Sprinkle with sesame seeds and chopped cilantro, if using, and serve hot.