Preheat oven to 400°F and line a baking sheet with parchment paper.
Press the tofu to remove excess moisture, then cut into 1-inch cubes.
Toss tofu cubes with cornstarch, sea salt, and black pepper until evenly coated.
Spread tofu on the baking sheet and bake for 25 minutes, flipping halfway, until golden and crispy.
While tofu bakes, whisk together peanut butter, tamari, sesame oil, maple syrup, rice vinegar, garlic powder, and ginger in a small bowl.
Steam the broccoli florets and shelled edamame until tender-crisp, about 5 minutes.
In a large bowl, combine the crispy tofu, steamed vegetables, and peanut sauce, tossing gently to coat everything.