HEAT oven to 350°F. Beat reduced-fat cream cheese and sugar in large bowl with mixer until well blended. Add egg whites and cinnamon; mix well. Gradually add milk, mixing well after each addition.
PLACE bread in 8-inch square baking dish; top with chocolate and cream cheese mixture.
BAKE 30 to 35 min. or until set in center. Cool slightly. Refrigerate leftovers.