Mix together with a wire whisk the mayo, honey, lime juice, sriracha, vinegar, and fish sauce. It can be served at room temp or cold.
In a mixing bowl, toss the shrimp with the salt, garlic powder, and pepper. Pour the buttermilk over seasoned shrimp; marinate for 15-20 minutes. Whisk together the flour, baking powder, panko, salt, and garlic powder. Coat shrimp in the breading and all let them rest while the oil heats.
Heat oil to 350 degrees in a skillet and fry in batches, being careful to not overcrowd the pan. Shrimp should cook for 2-3 minutes. They brown fairly quickly, so monitor the temperature. Drain on a wire rack.
Nutrition calculations do not include oil for frying.