Buffalo Chicken Burgers

Name: Buffalo Chicken Burgers
Ingredients: 3 large celery stalks, trimmed and very thinly sliced on an angle (about 1 3/4 cups); 1/4 cup sour cream; 2 1/2 ounces blue cheese, crumbled (about 1/2 cup), divided; 5 tablespoons chopped fresh parsley, divided; 1 1/2 teaspoons kosher salt, divided; 3/4 teaspoon black pepper, divided; 1 small red onion or sweet onion; 1 1/2 pounds ground chicken (white and dark meat); 1/4 cup panko; 1/2 teaspoon garlic powder; 6 tablespoons Frank’s RedHot Buffalo Wings hot sauce, divided; Canola oil, for greasing; 4 brioche hamburger buns, split and toasted; Carrot sticks and celery sticks, for serving (optional)