Heat 1/2-inch of oil in a large, heavy-bottomed skillet over medium heat. Line a large plate with a paper towel, set aside.
In a cake pan or pie plate whisk together eggs and buttermilk. Add 1/2 teaspoon of salt and pepper.
In another cake pan, mix together the flour, cornmeal, salt, pepper, garlic powder, onion powder, and cayenne pepper.
Add shrimp to the egg mixture and coat well. A few at a time, add the shrimp to the flour and coat completely. Place on a clean plate while you bread the remaining shrimp.
Add shrimp to skillet making sure not to overcrowd the pan. Fry for 3 minutes, until crispy and golden brown. Drain on prepared plate. Continue until all shrimp is fried.
Mix mayo and sweet chili sauce in a bowl for dipping.
Breading the shrimp with less mess:First, when you set up your little breading station you’ll want two pie plates or cake pans ideally. You can use bowls if necessary but the wide, shallow shape of pie or cake pans makes the process much easier.One cake pan will have the liquid ingredients, in this case, an egg and buttermilk. The second pan will hold the dry ingredients, flour, cornmeal and spices for a major flavor punch.Use one hand (I usually use my left since I move through the process left to right) to coat the shrimp in the egg mixture. Pick up the shrimp with the wet hand and place it in the flour mixture. Now use your other hand to gently coat the shrimp.Because you aren’t going back and forth with both hands they aren’t getting goopy and gross. One hand will have egg and one hand flour but not a big lumpy mess.