Prepare the Chicken:
In a large bowl, whisk together the buttermilk (or regular milk), egg, garlic powder, onion powder, ground ginger, salt, and pepper.
Add the chicken pieces to the marinade, and let them sit for at least 30 minutes (or up to 2 hours in the fridge for more flavor).
Coat the Chicken:
In a shallow dish, mix the flour, cornstarch, baking powder (optional), and a pinch of salt.
Once the chicken has marinated, remove it from the buttermilk mixture and coat the chicken pieces evenly in the flour mixture. Press gently to make sure the chicken is well-coated. Shake off any excess flour.
Fry the Chicken:
Heat about 2 inches of vegetable oil in a large frying pan over medium-high heat, or use a deep fryer if you have one.
Once the oil is hot (around 350°F or 175°C), fry the chicken pieces in batches, being careful not to overcrowd the pan. Fry for about 4-5 minutes or until the chicken is golden brown and crispy. Remove the chicken from the oil and place it on a paper towel-lined plate to drain any excess oil.
Make the Orange Sauce:
In a small saucepan, combine the fresh orange juice, sugar, soy sauce, rice vinegar, grated ginger, garlic, and chili paste or sriracha (if using). Stir everything together and bring to a simmer over medium heat.
Let the sauce simmer for about 4-5 minutes until it begins to thicken slightly.
In a small bowl, mix the cornstarch and water to make a slurry. Gradually add this to the sauce while stirring constantly to avoid lumps. Continue to cook for another 1-2 minutes until the sauce has thickened to your desired consistency.
Taste the sauce and adjust the seasoning if needed. If you like more heat, you can add more chili paste or sriracha.
Combine the Chicken and Sauce:
Once the chicken is fried and the sauce is ready, add the crispy chicken pieces to a large bowl.
Pour the orange sauce over the chicken and toss to coat evenly. If you like, you can garnish with orange zest or sesame seeds for added flavor and texture.
Serve:
Serve the crispy orange chicken over steamed white rice, or alongside some stir-fried vegetables. It’s perfect for a weeknight dinner or as part of a larger spread for a special occasion.