Cut the pressed tofu into about 3/4-inch cubes.
In a medium bowl, combine tamari, rice vinegar, maple syrup, garlic powder, and onion powder. Stir to combine.
Add the tofu to the marinade and gently toss to coat. Set aside for 10 to 15 minutes.
Preheat the oven to 375°F (190°C).
Line a rimmed baking sheet with parchment paper. Place the marinated tofu in a single layer on the sheet.
Bake for 25 to 30 minutes, tossing halfway through, until golden brown.
Serve immediately or store in a sealed container for 3 to 4 days.