Preheat the oven to 400°F and line a couple of baking sheets with parchment paper.
To make the baked tofu, first place the diced tofu into a medium bowl, along with the soy sauce, cornstarch, ginger, garlic powder, and oil. Stir gently to coat the tofu in the other ingredients.
Arrange the tofu cubes on one of the baking sheets, in a single layer.
Arrange the Brussels sprouts and sweet potato on the other baking sheet, covering half of the sheet with each veggie. Drizzle each type of vegetable with a teaspoon of oil and gently rub it in.
Place both baking sheets into the oven for about 20 minutes.
While the tofu and vegetables are in the oven, cook the rice according to the package directions (Note 1).
To make the peanut sauce, whisk all of the ingredients except the water together in a small bowl. Thin the mixture with as much water as is needed to create a creamy but pourable sauce. Taste-test the sauce and adjust any seasonings to your liking.
Remove the tofu from the oven when the pieces are browned and crispy. Remove the veggies from the oven when the sweet potato pieces are fork tender and the Brussels sprouts are browned. Give the veggies a sprinkle with salt and pepper.
Divide the rice among four bowls, then top each bowl with the tofu, vegetables, and sliced avocado. Drizzle with peanut sauce and sprinkle with scallions and sesame seeds. Serve.