MELT butter in medium microwave-safe bowl. Mix in Crust Mix until well blended. Reserve 1 tablespoon of crust-butter mixture for Decoration. Lightly press crust mixture up the side and onto bottom of 9" pie plate.
CHOCOLATE MOUSSE FILLING
ADD Filling Mix, 1 cup CARNATION® Evaporated Milk and 1 cup water to large mixer bowl. Mix on LOW speed for 30 seconds. Scrape bowl. Continue mixing on MEDIUM-HIGH speed until thickened, about 1 minute. Set aside.
ADD Topping Mix, remaining 1/2 cup CARNATION® Evaporated Milk and 1/2 cup water to small, dry mixer bowl. Mix on LOW speed for 30 seconds. Scrape bowl. Continue mixing on MEDIUM-HIGH speed, about 3 minutes. Topping will thicken and hold peaks.
FOLD whipped topping into chocolate cream filling until mixture is blended. Spoon into Chocolate Crust. Sprinkle with reserved crust-butter mixture.
REFRIGERATE for 3 hours or until firm.
For easier cutting and slice serving, carefully dip pie plate in very warm water for 30 seconds.