Marinate chicken for 2 hours to overnight.
Add oil and garlic to a pan and cook on medium heat until lightly browned then strain out the garlic.
Add sugar and water to a pan and cook on medium heat until sugar is dissolved. Add Thai chillies, lime juice, and fish sauce and cook until slightly thickened(5 minutes).
Combine tapioca starch, rice flour, and baking powder then thoroughly coat marinated chicken in the flour mixture.
Fry chicken at 350°F for 7-8 minutes then rest on a wire rack. Fry again at 375°F for 2 more minutes until golden brown.
Coat chicken in sauce and sprinkle fried garlic on top.
