1. Prepare the magic sauce by whisking together mayonnaise, 2 tablespoons of maple syrup, and Dijon mustard; set aside.
2. Heat 2 tablespoons of canola oil in a skillet over medium heat; cook the onion with half of the chopped apple until the onion is tender, about 7-10 minutes. Set aside.
3. In a large bowl, combine the other half of the apple (uncooked), ground chicken, 2 tablespoons of maple syrup, Italian seasoning, egg, salt, and pepper. Shape this mixture into 6 patties (the mixture will not be too compact... that's okay).
4. Heat 1 tablespoon of canola oil in a skillet over medium heat and place a patty in it. Flatten slightly with a spatula and cook for about 5-7 minutes per side, until the center is no longer pink; repeat for each patty.
5. Assemble the burgers: place a cooked patty in each bun, then top with the onion-apple mixture, and spread the inside of the bun with the magic sauce.