Use a meat cleaver to cut the Chicken Legs in half. In a large bowl, add the Salt, Black Pepper, and Ginger, and mix well with the Chicken.
In another bowl, add the Cornstarch and Baking Powder, cover the Chicken pieces one at a time and shake off any extra starch.
Put the coated Chicken pieces in a different bowl and set aside.
In a wok or frying pan, add the Vegetable Oil and first-fry one-half of the Chicken on medium-high heat for 12 minutes until slightly browned.
Remove the chicken and drain. Repeat the process for the rest of the chicken: fry and drain.
For the second fry (the double fry), return all the Chicken to the wok and fry on medium-high heat for another 10 minutes until golden brown.
Drain the Chicken and set aside.
Fry the Walnuts in the same oil for about 30 seconds. Set aside.
Clean the wok and return to medium heat. Add the Vegetable Oil, Garlic, and Dry Red Peppers and stir for about 20 seconds. Then add the Soy Sauce, Vanilla Syrup, Rice Vinegar, and Chili Flakes. Stir for another 15 seconds until all the sauces are well combined, then add the Brown Sugar.
Add the fried Chicken pieces and Walnuts. Coat well with the sauce. Before serving, add the Sesame Seeds for garnish.