Drain banana peppers and pat them as dry as possible with paper towels. Lay them in a single layer on paper towels or a clean kitchen towel and let them air dry for at least 15 minutes.
While peppers are drying, set up three shallow bowls. In the first, add flour. In the second, gently beat eggs with hot sauce (if using). In the third, whisk together cornmeal, panko, garlic powder, paprika, onion powder, salt, and pepper.
Pour enough oil into a deep skillet so that it comes up about 1 to 1 ½ inches up the side. Heat over medium-high heat until oil registers between 350-375 on a thermometer.
While oil is heating, toss peppers in flour to coat. Shake off excess flour and dunk them in the beaten eggs. Finally, dredge in the cornmeal mixture, pressing on coating to help it stick.
Working in batches so as to not overcrowd skillet, carefully drop peppers in hot oil and fry 1-2 minutes per side, until golden and crispy.
Remove peppers to paper towel-lined plate and immediately sprinkle with flaky salt.
Continue until all peppers are fried. Serve with chipotle aioli or dipping sauce of choice.