Heat oven to 350 degrees. Place turkey in large bowl. Add remaining burger ingredients except cheese; work in gently by hand. Divide mixture into 8 equal pieces.
Flatten each piece into round patty. Top 4 of the patties with a piece of cheese and then with second patty. By hand, press edges together to seal and make patties of even thickness.
On separate sheets of waxed paper, place seasoned flour and panko bread crumbs. In shallow bowl, beat egg lightly. Coat patties lightly with flour mixture, dip into egg and then coat with bread crumbs, pressing crumbs gently onto patties.