Press the block of tofu between clean towels with a weight on top for about 15-20 minutes until most of the moisture is removed. This will help it crisp up nicely during baking.
Once pressed, cut the tofu into evenly-sized bite-sized cubes, about 2 cm (0.8 inch) each. Keep the pieces uniform for even baking and crisping.
In a small bowl, mix the cornstarch with a pinch of salt and pepper, then toss the tofu cubes in this mixture until each piece is lightly coated. Shake off any excess to avoid clumping.
In a large bowl, whisk together soy sauce, sesame oil, and a splash of water. Add the panko breadcrumbs and stir to combine, creating a seasoned coating mixture.
Gently toss the cornstarch-coated tofu in the breadcrumb mixture, pressing lightly to help the coating adhere evenly to each piece.
Arrange the coated tofu nuggets on the prepared baking sheet, leaving space between each piece. Lightly spray the nuggets with cooking spray to promote crispness and golden color.
Bake the nuggets in a preheated oven at 200°C (390°F) for 25-30 minutes, flipping them halfway through. They should turn golden brown and crackle when shaken.
Remove the baking sheet from the oven and let the nuggets rest for about 5 minutes. This allows the crust to set further and enhances crunchiness.
Squeeze fresh lemon juice over the nuggets just before serving for a bright, zesty finish. Serve immediately with dipping sauces or atop salads.
