In a shallow bowl, mix flour, salt, pepper, and garlic powder. Set aside.
In another shallow bowl, whisk eggs with ⅓ cup of water. Set aside.
Pile breadcrumbs onto a plate, set aside.
On another plate, sprinkle a light coating of panko and set aside.
Carefully cut shrimp along the back and lay it open. Be careful not to cut all the way through the shrimp.
Coat shrimp in flour, shaking to remove excess flour. Then, dip shrimp into egg, allowing excess egg to drip back into egg bowl.
Place egg-coated shrimp into panko bread crumbs, cover with panko and press lightly, making sure all shrimp is covered with panko and the shrimp has remained open. Place coated shrimp onto the plate that was sprinkled with panko.
Continue coating shrimp, adding panko to the plate as needed. You may need to use all 4 cups of panko, depending on the size of shrimp and thickness of egg wash left on shrimp.
Once all shrimp have been coated and placed on the plate, place plate in the refrigerator for at least 30 minutes and up to 5 hours.
Heat oil in a medium-size pan over medium-high heat until oil sizzles when a few panko crumbs are tossed in the pan.
Fry shrimp in hot oil until shrimp are golden brown. Be careful not to overcook.
Serve immediately with cocktail sauce and lemons.
Notes
Nutritional data assumes there are 30 shrimp per pound and 1 teaspoon flour, breadcrumbs and oil remain on each individual shrimp. Nutritional data will vary greatly in this recipe depending on oil temperature and amount of oil retained during cooking.