In a large bowl, combine the flour, cornstarch, baking powder, salt, and black pepper. Mix well.
Add the chicken pieces to the bowl and toss them in the flour mixture until evenly coated.
Heat the vegetable oil in a frying pan or wok over medium-high heat.
Once the oil is hot, carefully add the coated chicken pieces. Fry them in batches for about 5-7 minutes or until they are golden brown and crispy. Use a slotted spoon to remove the chicken and place it on paper towels to drain excess oil.
In a separate bowl, whisk together the honey, soy sauce, minced garlic, rice vinegar, sesame oil, and red pepper flakes until well combined.
In the same pan, remove excess oil, leaving about 1 tablespoon. Pour the honey garlic sauce into the pan and bring to a simmer over medium heat.
Add the crispy chicken pieces to the sauce and toss to coat thoroughly. Cook for an additional 2-3 minutes, allowing the sauce to thicken.
Remove from heat and garnish with chopped green onions before serving.
Serve the crispy chicken over steamed rice or with a side of stir-fried vegetables for a complete meal.