Cut artichoke hearts in half lengthwise and pat dry with paper towels.
In a shallow bowl, combine flour, salt, garlic powder, and several grinds of pepper. In another shallow bowl, whisk eggs and 2 tablespoons Buffalo sauce. Place panko in a third shallow bowl.
Working one at a time, toss artichokes in flour mixture, then dip in egg, then finally in panko, making sure artichoke is well coated after each. Transfer to a baking sheet.
Into a large heavy pot fitted with a deep-fry thermometer, pour oil to a depth of 2". Heat over medium-high heat until thermometer registers 370°. Working in batches, fry artichokes until deeply golden, 3 to 4 minutes. Transfer to a paper towel-lined plate. Adjust heat as needed between batches.
In a small pot over medium heat, heat remaining ⅔ cup Buffalo sauce until just warmed through but not boiling.
Transfer fried artichokes to a large bowl and pour warmed sauce over. Toss to coat. Serve hot with ranch dressing alongside.
