Press and Cube Tofu : Pat the pressed tofu block completely dry with paper towels. Cut the block into uniform ¾-inch cubes to ensure even cooking.
Prepare the Savory Marinade : In a small bowl, whisk together the balsamic vinegar, tamari, avocado oil, smoked paprika, and fine sea salt until fully combined.
Infuse the Tofu : Place the tofu cubes in the shallow glass baking dish in a single layer. Pour the prepared marinade over the tofu. Use a silicone spatula to gently turn the cubes, ensuring each piece is coated. Let marinate at room temperature for 45 minutes, turning the pieces once midway through.
Preheat and Prepare : While the tofu marinates, adjust an oven rack to the middle position and preheat to 425°F (220°C). Line the rimmed baking pan with a sheet of parchment paper.
Initial Bake : Pour the tofu cubes and all the marinade from the dish onto the prepared baking pan. Spread the cubes into a single layer, making sure they are not overcrowded. Bake for 20 to 25 minutes, or until most of the liquid has been absorbed and the tofu is firm to the touch.
Final Glazing Roast : Remove the pan from the oven. Drizzle the agave nectar evenly over the tofu. Gently toss the cubes on the pan to coat them in the developing glaze. Return the pan to the oven and roast for an additional 5 to 7 minutes, until the glaze is sticky and the edges of the tofu are deeply browned and crisp.
Garnish and Serve : Transfer the finished tofu bites to a serving dish. Top with a sprinkle of fresh, thinly sliced scallions before serving immediately.