Preheat the oven to 400F/205C and line a baking sheet with parchment paper or a silicone mat. Set aside.
Prep the tofu. Cut and cube the tofu into small cubes, either 1-inch cubes or smaller. Place into a medium sized bowl. Drizzle over 1 tablespoon of soy sauce and cornstarch. Using a spatula, carefully stir to coat each cube.
Bake the first round. Place the tofu on the prepared baking sheet. Bake for 10 to 12 minutes, or until the tofu is crispy.
Mix the sauce. While the tofu is baking, mix the sauce together. In a small bowl, combine the ketchup, remaining soy sauce, brown sugar (or other sweetener of choice), and the garlic powder.
Put it together and bake the second round. Remove the tofu from the oven and stir the sauce over top. Place the tofu back in the oven and bake again for another 7 to 10 minutes. The tofu is ready when the tofu is browned and the sauce has some browning as well. Remove from the oven, top with desired toppings, and enjoy!
