Cut each cake roll into 8 slices; set aside any of the chocolate coating that separates from rolls for garnish. Line a 9 in. springform pan with cake slices, completely covering bottom and sides.
In a small bowl, whisk milk and pudding mixes for 2 minutes. Let stand for 2 minutes or until soft set. Pour over cake. Spread with whipped topping; sprinkle with any reserved chocolate coating. Cover and refrigerate for at least 2 hours. You can also add chocolate shavings and cocoa powder.