In a large bowl, combine ground chicken, chopped apple, maple syrup, Dijon mustard, breadcrumbs, beaten egg, garlic powder, salt, and pepper.
Cover the bowl and refrigerate for at least 30 minutes.
Preheat your grill or a large skillet over medium heat.
Form the chilled mixture into burger patties, about 1/2-inch thick.
Cook the patties for about 5-6 minutes on each side, or until they reach an internal temperature of 165°F.
Remove the burgers from the grill and let them rest for a few minutes.
Assemble the burgers on buns and serve with your favorite toppings.