If deep frying, in a deep fryer or cast iron pot, heat 6-8 cups of oil to 375 degrees. If pan frying, heat 1 1/2-2 cups oil (about 1/2 inch in the pan) in a large, heavy bottomed frying pan.
In a large bowl or pie pan, whisk together hot sauce, water, and egg.
In a shallow bowl or pie pan, combine flour, salt, cayenne pepper, black pepper, onion powder, paprika, and garlic powder.
Pound each chicken breast with a mallet/tenderizer until about 3/8 inch thick. The chicken may be much larger than the bun when it’s pounded thin. If so, you may want to cut the breast in half before breading to make the chicken fit better on the bun.
Coat each fillet in the flour, then in the hot sauce/water/egg mixture, then in the flour again. Repeat the dredge if you would like a thicker coating.
After all of the chicken is coated, deep fry for 8 to 12 minutes, or pan fry 4 to 6 minutes on each side. After frying, drain excess oil from the chicken by placing it on a cooling rack or on a plate covered with paper towels.
Grill the faces of the hamburger buns on a griddle or in a dry skillet (optional) and prepare sandwiches with chicken, mayonnaise, lettuce, and tomato.