Prepare the Chicken

1. In a bowl, combine the cornstarch, flour, baking powder, salt, and pepper. Mix well.
2. In another bowl, beat the egg and add cold water to it.
3. Dip the chicken pieces into the egg mixture, then dredge them in the flour-cornstarch mixture until fully coated.

Fry the Chicken

1. Heat vegetable oil in a deep skillet or wok over medium-high heat. The oil should be hot enough that a small piece of chicken sizzles when added.
2. Fry the chicken in batches, making sure not to overcrowd the pan. Cook for 4-5 minutes per batch, turning occasionally, until golden brown and crispy.
3. Remove the chicken from the oil and place it on a paper towel-lined plate to drain any excess oil.

Make the Honey Garlic Sauce

1. In a separate pan or skillet, combine the honey, soy sauce, garlic, rice vinegar, sesame oil, ginger, and red pepper flakes (if using).
2. Bring the mixture to a simmer over medium heat, stirring frequently.
3. Allow the sauce to simmer for about 2-3 minutes, letting the flavors meld together.
4. If you prefer a thicker sauce, stir in the cornstarch-water mixture and cook for another 1-2 minutes until thickened.

Combine Chicken with Sauce

1. Once the sauce has thickened, add the crispy chicken pieces into the sauce.
2. Stir gently to coat the chicken evenly in the honey garlic sauce.
3. Cook for another 1-2 minutes to allow the chicken to absorb the sauce.