Taiwanese Popcorn Chicken

In a medium bowl, whisk together all marinade ingredients except for the chicken until smooth. Add chicken and toss to coat. Let sit for 30 minutes. In a medium pot over medium-high heat, heat 1” of peanut oil to 325°. In a large bowl, mix together cornstarch, baking powder, and 1 teaspoon five spice powder. In a small bowl, combine remaining 1 teaspoon five spice powder, white pepper, black pepper, and gochugaru (if using). Add drained marinated chicken to cornstarch mixture and toss to coat evenly and completely. In 3 to 4 batches, add coated chicken to heated oil and fry until golden, being sure not to overcrowd the pot, 3 to 4 minutes. Remove fried chicken from oil and place into a large mixing bowl lined with a paper towel.  Increase frying oil to 375°. In 2 to 3 batches, re-fry chicken until deeply golden and seriously crispy, 2 to 3 minutes. Transfer each batch to the bowl as it’s done, and sprinkle with five spice powder mixture, salt, and MSG (if using) while hot. Repeat with remaining chicken. Remove paper towel from bowl, add in all remaining five spice powder, and toss until chicken is evenly coated. Add basil leaves to frying oil and fry until translucent, 20 to 30 seconds. Remove from oil and place on top of fried chicken.