Preheat oil in a deep skillet to 350°F (175°C). Pound chicken breasts to about half an inch thick.
Set up three bowls: one with seasoned flour (salt, pepper, garlic powder), one with beaten eggs, and one with panko breadcrumbs.
Dredge each chicken breast in flour, dip in eggs, and coat with breadcrumbs.
Fry breaded chicken for 5-7 minutes on each side until golden brown. Drain on paper towels.
Mix mayonnaise and hot sauce for the sauce; adjust spice level as desired.
Assemble sandwiches by spreading sauce on bread, adding crispy chicken, and any additional toppings.