PREHEAT oven to 350°F. Toss bread cubes with apples and walnuts; place in lightly greased 13x9-inch baking pan.
POUR milk into large bowl. Add dry pudding mixes and 1 tsp. of the cinnamon. Beat with wire whisk 2 minutes. Pour over bread mixture; sprinkle with remaining 1 tsp. cinnamon.
BAKE 50 minutes to 1 hour or until hot and bubbly. Let stand 10 minutes before serving. Top with whipped topping just before serving.