Preheat oven to 400 degrees and line a baking sheet with parchment paper or foil. Place a wire rack over the top of the baking sheet and spray it lightly with cooking oil (I like to use avocado oil).
Pat shrimp with paper towels to ensure they're as dry as possible. You can leave the tails on or remove them. I like to leave them on for visual appeal.
In a shallow dish, whisk together flour, garlic powder, paprika, and salt.
In a second shallow dish, whisk together egg and water.
In a third shallow dish, add panko.
Dredge each shrimp in the flour mixture, shaking off any excess. Then dunk it fully in the egg mixture to coat. Lastly, press the shrimp into the panko, ensuring an even coating on all sides.
Place shrimp in a single layer on the prepared rack set over the baking pan. Lightly spray the shrimp with cooking oil.
Bake for 10-12 minutes, until shrimp are cooked through and panko is just starting to turn golden, flipping the shrimp about halfway through baking time. When you remove the shrimp, keep the oven on.
While the shrimp are baking, add the butter to a small saucepan set over low heat and let melt. Stir in the buffalo sauce until combined and heated through.
When shrimp are out of the oven, add them to a large bowl and pour buffalo sauce over them. Toss gently to coat evenly.
Return to wire rack over baking sheet and put back in oven for another 3-4 minutes to crisp them up.