Taiwanese Popcorn Chicken With Furu Fermented Bean Curd

Name: Taiwanese Popcorn Chicken With Furu (Fermented Bean Curd)
Ingredients: For the chicken:; 1 pound (450g) boneless skin-on chicken thighs, cut into 1-inch (2.5cm) chunks; 2 tablespoons (30ml) fermented bean curd (furu), any flavor; 1/2 tablespoon (8ml) Taiwanese or Japanese soy sauce; 1 1/2 tablespoons (22ml) Shaoxing wine; 2 medium cloves garlic, minced; 2 teaspoons (8g) granulated sugar; 1/2 teaspoon ground white pepper; 1/4 teaspoon five-spice powder; 1 1/2 tablespoons (12g) all-purpose flour; 1/4 teaspoon baking powder; 1 cup (160g) thick sweet potato starch (see note); 4 cups (1L) neutral oil, such as soybean or canola; For the seasoning:; 1/2 teaspoon chile powder, such as cayenne; 1/2 teaspoon Diamond Crystal kosher salt, plus more as needed