Combine chicken, eggs, garlic, soy sauce, rice wine, vegetable oil, sugar, salt, and five-spice powder in a large bowl. Mix well, ensuring every piece is coated. Refrigerate for at least one hour, but preferably overnight, for the deepest flavor penetration.

Dredge each piece of chicken in coarse tapioca or sweet potato starch. The starch should cling generously; let the coated pieces rest briefly on a rack so the surface absorbs moisture—this creates the popcorn-like crunch Taiwanese fried chicken is famous for.

Heat oil in a heavy pot or deep fryer to 300°F. Fry the chicken in batches, careful not to crowd the pan. After 2–3 minutes, when lightly golden but not fully cooked, remove and set aside. Raise the oil to 340°F, then return the chicken for a second fry. This step fully cooks the chicken and yields a drier, crispier crust that seals in juiciness. If you don't have a thermometer, use medium to medium-high heat, then increase the heat for the second fry. I usually use a skewer or chopstick and dip it in the oil - if you see steady, consistent bubbles forming around the wood, the oil is ready for frying.

When the last batch is nearly done, add the Thai basil leaves to the hot oil and cook for about 10 seconds. The basil will turn crisp and aromatic—watch for oil splatter as the water content causes the leaves to pop.

Use a strainer to remove the chicken and Thai basil from the pot and drain on paper towels to remove excess oil.

While still hot, sprinkle with pepper salt or chili powder, if desired. Serve immediately for that authentic Taiwanese night market experience.