Prepare the Shrimp: Rinse shrimp under cold water, pat dry with paper towels. Place them in a bowl with buttermilk. Let them soak for 10 minutes (this helps tenderize and coat them for dredging).
Prepare the Coating: In a large bowl, whisk together cornstarch, flour, garlic powder, paprika, salt, and pepper.
Heat the Oil: Pour enough oil into a deep skillet or Dutch oven to cover shrimp (about 2 inches deep). Heat to 350°F (175°C).
Coat and Fry Shrimp: Remove shrimp from buttermilk, shake off excess liquid. Dredge in the flour-cornstarch mixture, pressing lightly to coat evenly. Fry in small batches for 2–3 minutes until golden brown and crispy. Remove with slotted spoon and drain on paper towels.
Make the Sauce: In a medium bowl, whisk together mayonnaise, sweet chili sauce, sriracha, honey, and vinegar/lime juice until smooth.
Combine Shrimp and Sauce: Toss fried shrimp in the sauce until coated evenly. Alternatively, serve the sauce on the side for dipping (to maintain maximum crispiness).
Garnish u0026 Serve: Sprinkle with green onions, sesame seeds, or fresh herbs before serving.