PLACE butter in 2-qt. microwaveable round dish at least 2 inches deep. Microwave on HIGH 30 sec. or until melted. Add 1/2 cup graham crumbs, 1/3 cup sugar, nuts and 1 tsp. cinnamon; mix well. Set aside.
BEAT eggs in large bowl with wire whisk. Add COOL WHIP, remaining graham crumbs, sugar and cinnamon; stir just until blended. Spread over crumb mixture in dish.
MICROWAVE on MEDIUM (50%) 9 to 10 min. or until cake starts to pull away from side of dish, turning dish after 5 min. (Top will still be slightly moist.) Place serving plate on top of dish; invert cake. Remove dish. Sprinkle any crumbs remaining on bottom of dish over cake. Fluff crumb topping with fork. Serve warm.