Cut chicken breasts into bite-sized pieces.
Place chicken pieces in buttermilk in a medium bowl, cover, and refrigerate for at least 30 minutes.
In a large bowl, whisk together flour, garlic powder, onion powder, paprika, salt, and black pepper.
Remove chicken from buttermilk, letting excess drip off, then coat pieces thoroughly with the flour mixture.
Allow coated chicken to rest on a wire rack for about 10 minutes.
In a small bowl, combine mayonnaise, sweet chili sauce, sriracha, lime juice, and honey; mix well and set aside.
Heat vegetable oil in a skillet to 350°F (175°C) to 1/2 inch depth.
Fry chicken pieces in batches for 4-5 minutes per side until golden brown and cooked through.
Drain fried chicken on paper towels and repeat with remaining pieces.
Serve chicken plated with Bang Bang sauce drizzled on top or on the side for dipping.
Garnish with chopped green onions or sesame seeds, if desired.