Pat the large shrimp very dry using paper towels and preheat oil in a skillet or Dutch oven over medium heat until it reaches 350°F (175°C).

In a mixing bowl, combine the all-purpose flour, cornstarch, baking powder, salt, and black pepper. Whisk until well blended.

In another bowl, beat the egg and add water. Slowly pour this into the dry ingredients, stirring until smooth.

Dip the prepared shrimp into the batter, ensuring an even coating. Allow excess batter to drip off.

Fry the battered shrimp in small batches for about 2-3 minutes until light golden. Drain on a wire rack.

Let the fried shrimp rest for about 5 minutes, then increase oil temperature to 375°F (190°C) for the second fry.

Return the shrimp to the hot oil for a second frying for 1-2 minutes until crispy and golden.

Whisk together the mayonnaise, sweetened condensed milk, honey, lemon juice, and a pinch of salt in a bowl until smooth.

Toast the pecans in a skillet over medium heat for 3-5 minutes until fragrant and lightly browned.

Gently toss the warm, fried shrimp in the prepared glaze just before serving.

Plate the glazed shrimp and sprinkle with toasted pecans and sliced green onions.