Preheat oven to 220°C / 425°F.
Line a baking tray with aluminum foil. Spray the surface of the foil lightly with cooking spray.
Drain tofu and cut into 0.5 inch slices. Pat dry with paper towels.
Prepare three bowls. Place cornstarch in the first one, beaten egg in the second one, and breadcrumbs and salt in the third one.
Pick up a slice of tofu and coat it in cornstarch, then in the egg, then finally in the breadcrumbs. Press down firmly to help the breadcrumbs adhere. Transfer to baking tray.
Repeat for the rest of the tofu slices.
Spray the crumbed tofu lightly with cooking spray, then transfer to oven. Bake for 10 minutes, flip, then bake for 5 more minutes.