Make cake according to directions on the box. Let cool slightly, then using the handle of a wooden spoon, poke holes in top of the cake. Let cool completely.
Put espresso powder in a 2 cup measuring cup. Add hot water and mix until powder has dissolved. Next, add enough milk to reach the 1 ¾ mark on your measuring cup. Add this mixture to the vanilla pudding mix and whisk together. Let set several minutes until the pudding starts to thicken. Then poor the pudding over the cake filling all the holes. Place the cake in the refrigerator and let the pudding set.
Mix the cream and powdered sugar together using the electric mixer until the whipped topping thickens and peaks start to form. Careful not to over mix.
Carefully spread the topping over the cake.
Use a vegetable peeler on the chocolate bar to make chocolate curls. Sprinkle the chocolate curls over the cake. Refrigerate a couple of hours before serving. Store remaining cake in refrigerator. Enjoy!