Peel and devein the jumbo shrimp. Rinse under cold water to remove any tiny shell fragments, then pat completely dry with paper towels.

Arrange 3 shallow plates. In the first, whisk together all the listed flour-mixture ingredients. In the second, beat the egg. In the third, evenly spread the panko breadcrumbs.

Working one shrimp at a time, evenly coat each piece in the flour mixture and shake off the excess. Coat in beaten egg, then firmly press into the panko for an even coating. Set aside on a parchment-lined baking sheet.

Heat the oil to 350°F (175°C) in a heavy-bottomed pan, adjusting the heat as needed. Fry 5-6 shrimp at a time for 2-3 minutes, flipping halfway through, until golden and the shrimp form a C-curl. Cooked shrimp should reach an internal temperature of 145°F. Remove the shrimp with tongs or a slotted spoon. Let the oil return to 350°F between batches, removing any browned bits from the oil as needed.

Transfer the fried shrimp to a wire rack to drain in a single layer.