Preheat the oven to 400°F and line a large, rimmed baking sheet with parchment paper to prevent the tofu from sticking.

Drain the tofu and gently press out some of the excess water using your hands. Slice the tofu lengthwise into 3 even slabs. Stack the slabs, then cut them into 3 lengthwise columns and 5 crosswise rows, creating cubes.

Place a lint-free tea towel or paper towels on a cutting board, and spread the tofu cubes in an even layer on top. Fold the towel over the tofu and place a heavy object (like another cutting board with a cast iron pan or canned goods on top) to help press out the moisture. Let the tofu drain for at least 10 minutes, or up to 30 minutes if time allows.

Transfer the drained tofu to a medium bowl. Drizzle with olive oil and tamari, then toss to coat. Sprinkle cornstarch over the tofu and toss again until evenly coated, ensuring there are no powdery spots.

Pour the tofu onto the prepared baking sheet and spread it in an even layer. Bake for 25 to 30 minutes, tossing halfway through, until the edges are crispy and golden.

Use the crispy tofu as desired in your favorite dish.