Press the tofu for 15-20 minutes to remove excess water, then cut into 1-inch cubes.
In a bowl, whisk together the soy sauce, rice vinegar, sesame oil, maple syrup, ginger, and garlic.
Toss the tofu cubes in the marinade and let sit for at least 15 minutes (or up to overnight in the fridge).
Preheat the oven to 400°F (200°C) and line a baking sheet with parchment paper.
Drain the tofu, reserving the marinade. Toss the tofu cubes with cornstarch until lightly coated.
Arrange the tofu in a single layer on the baking sheet. Bake for 25-30 minutes, flipping halfway through, until golden and crispy.
In the last few minutes of baking, brush or toss the tofu with the reserved marinade for extra flavor.
Serve hot over rice, garnished with sliced scallions and sesame seeds.