Prep the shrimp: Pat the shrimp dry with paper towels. Dry shrimp crisp better.
Set aside while you make the batter and sauce.
Make the orange sauce: In a small bowl, whisk orange juice, zest, soy sauce, rice vinegar, and honey. Stir in ginger, garlic, and chili-garlic sauce if using. Set the cornstarch slurry aside separately.
Cook the sauce: Pour the sauce mixture into a small saucepan over medium heat.
Bring to a gentle simmer. Whisk in the cornstarch slurry and cook 1–2 minutes until glossy and slightly thick. Turn off the heat and stir in sesame oil.
Taste and adjust sweetness, salt, or heat.
Heat the oil: Pour 1–1.5 inches of oil into a deep skillet or saucepan. Heat to 350–360°F. If you don’t have a thermometer, a drop of batter should sizzle and float within 2–3 seconds.
Mix the coating: In a medium bowl, whisk cornstarch, flour, baking powder, garlic powder, salt, and pepper.
Add the egg and cold club soda, whisking just until smooth. The batter should be pourable and light, like thin pancake batter.
Batter the shrimp: Add the shrimp to the batter and toss to coat evenly. Let excess drip off before frying.
Fry in batches: Carefully lower shrimp into the hot oil, spacing them out.
Fry 2–3 minutes, turning once, until golden and crisp. Do not overcrowd the pan. Transfer to a wire rack or paper towel–lined plate.
Repeat with remaining shrimp.
Toss with sauce: Add the fried shrimp to a large bowl. Drizzle warm orange sauce over the top and toss gently to coat. Use just enough sauce to glaze; extra can be served on the side.
Garnish and serve: Sprinkle with green onions and sesame seeds.
Serve immediately over rice, noodles, or greens.