Prepare pudding as directed on box and chill.
Cut cake into cubes and put a single layer in a trifle or tall glass bowl. Spread a layer of pudding over cake. Spread a layer of Cool Whip over pudding. Sprinkle a cup of toffee chips over Cool Whip. Begin again layering each item to the top of the bowl. End with Cool Whip and toffee chips. Chill until ready to serve.
