Pat the shrimp dry with paper towels. If tails are on, leave them for presentation or remove if preferred. Place shrimp in a bowl and toss with kosher salt (1 tsp), black pepper (1 tsp), garlic powder (1 tsp) and lemon juice (1 tbs). Let sit while you prepare the batter, about 5–10 minutes.

Batter & Coating

Make the batter

In a medium bowl, whisk together all-purpose flour (3 tbs), cornstarch (3 tbs) and baking powder (1 tsp). Lightly beat the egg, then add it to the dry mixture along with cold club soda (1 cup). Whisk briefly until just combined — the batter should be slightly lumpy and thin enough to coat but not run off instantly. Keep the batter cold (you can set the bowl over another bowl with ice briefly).

Prep panko

Place panko breadcrumbs (1 cup) in a shallow dish. This will be used as the outer coating for crunch.

Frying

Heat oil

Pour neutral oil (about 2 cups; enough to reach roughly 2 inches deep) into a heavy-bottomed skillet or a medium pot. Heat over medium-high until a deep-fry thermometer reads 350°F (175°C). If you don't have a thermometer, test with a small drop of batter — it should sizzle and rise immediately.

Batter and coat shrimp

Working in batches of 3–4 shrimp to avoid crowding, dip each seasoned shrimp into the cold batter, letting excess drip off for 2–3 seconds, then immediately press into the panko so the crumbs adhere and cover evenly. Place coated shrimp on a tray while heating the oil and do not let them sit long in batter to avoid sogginess.

Fry

Carefully lower 3–4 coated shrimp into the hot oil. Fry until golden brown and crisp, about 2–3 minutes per side (total 3–5 minutes) depending on shrimp size. Do not overcrowd the pan. Use a slotted spoon or spider to turn once if needed. When done, transfer to a wire rack set over a baking sheet or paper towels to drain. Keep cooked shrimp warm in a 200°F (95°C) oven while finishing remaining batches.

Spicy Mayo & Finish

Make spicy mayo

In a small bowl, whisk together mayonnaise (1 tbs), Sriracha (1 tbs), sweet chili sauce (1 tsp), rice vinegar (1 tsp), sesame oil (1 tsp) and sugar (1 tsp) until smooth. Taste and adjust heat or sweetness as desired. Fold in thinly sliced scallion (1 tbs) or reserve scallion for garnish.

Plate and serve

Arrange shredded cabbage or mixed greens (1 cup) on serving plates if using. Place 12 fried shrimp on the bed. Drizzle or dollop spicy mayo over the shrimp (you can also serve the mayo on the side). Garnish with additional sliced scallion and lemon wedges. Serve immediately so shrimp remain crisp.