Press the tofu for 20 minutes. Remove the tofu from the container. Add the block to a tofu press, or wrap the tofu in a paper towel and place a large, heavy pan on top.
While your tofu is pressing. Whisk together the soy sauce, rice vinegar, minced garlic, and sesame oil in a small bowl.
Tear the block into 1-inch pieces once the tofu is pressed.
Top the tofu pieces with marinade. Cover and refrigerate for 30 minutes.
While the tofu marinates, prepare the three bowls for dipping the nuggets. In the first bowl, combine the flour and cornstarch. In the second bowl, combine the soy milk and the apple cider vinegar (allow to sit for 10 minutes). Combine the panko breadcrumbs, nutritional yeast, garlic powder, onion powder, salt, and pepper in the third bowl.
Preheat the oven to 400 degrees Fahrenheit. Once the tofu has had time to marinate, please remove it from the refrigerator. Using a fork, place one tofu nugget at a time in the flour mixture covering all sides, then in the vegan buttermilk, and last in the panko breadcrumbs. Place the nuggets on a baking sheet lined with parchment paper or aluminum foil. If using foil, spray with cooking spray to keep the nuggets from sticking. Repeat with each tofu nugget until all have been breaded.
Place the baking sheet on the middle rack in the oven. Bake for 20 minutes, turning them over at the 10-minute mark to bake evenly and crisp on all sides.