Prepare cake layers: Heat oven to 350 Grease 9 x 13 pan. Prepare batter for devil's food cake as directed but using 1 egg, 1/2 c. Oil and no water; pat evenly into prepared pan. Bake 15 to 18 minutes until dry to touch. Remove pan from oven, maintaining oven temperature; sprinkle hot crust with chocolate chips. Let stand 2 to 3 minutes. Using metal spatula, smooth chocolate into thin, even layer; set pan aside. Prepare white cake mix according to package directions, beating in drink mix, pour batter over crust. Bake 50 to 55 minutes until wooden pick inserted in center comes out clean. Cool in pan. Prepare frosting: In large bowl with electric mixer at high speed, beat cream and powdered sugar until stiff. To serve. Loosen cake from pan; invert onto wire rack. Using second rack, invert again so crust is on bottom. Spread cream over top of cake; decorate with walnuts and cocoa powder. Makes 16 servings. Calories: 597