Prepare the Chicken:
Preheat Oven: Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or a wire rack.
Coat the Chicken: In a bowl, mix the flour, cornstarch, salt, pepper, and garlic powder. In a separate bowl, whisk the eggs. Dip each chicken piece into the flour mixture, then into the beaten eggs, and back into the flour mixture to coat well.
Bake the Chicken: Place the coated chicken pieces on the prepared baking sheet. Lightly drizzle or spray with vegetable oil. Bake for 25-30 minutes, flipping halfway through, until the chicken is crispy and cooked through.
Make the Orange Sauce:
Mix Sauce Ingredients: In a medium saucepan, combine the orange juice, orange zest, honey, soy sauce, rice vinegar, sesame oil, garlic, and ginger. Heat over medium heat, stirring occasionally.
Thicken the Sauce: Once the sauce is hot, stir in the cornstarch slurry. Simmer for 2-3 minutes until the sauce thickens.
Combine and Serve:
Coat the Chicken: Toss the baked chicken pieces in the orange sauce until evenly coated.
Garnish and Serve: Transfer the orange chicken to a serving dish and garnish with sesame seeds and sliced green onions. Serve over steamed rice or with stir-fried vegetables.