Press tofu between paper towels or using a tofu press to remove excess moisture, then cut into 1-inch cubes.
Preheat oven to 450°F and line a baking sheet with parchment paper, lightly oiling the surface.
In a bowl, toss tofu cubes with sweet potato starch until evenly coated.
Arrange coated tofu on prepared baking sheet, brush tops with oil, and sprinkle with salt.
Bake for 30-35 minutes until golden brown and crispy on all sides.
While tofu bakes, whisk together mayo, honey, and a pinch of salt in a large bowl.
Remove tofu from oven and immediately toss hot tofu cubes in the honey-mayo sauce.
Transfer to serving plate and garnish with toasted sesame seeds and candied walnuts if using.