Make the Devil’s Food cake. Bake it according to the instructions on the box.
After it's done and still slightly warm, grab a wooden spoon. Holding it by the spoon end, poke holes in the cake. Space them evenly and make sure that the holes go deep but not all the way through.
Slowly pour the sweetened condensed milk into the holes. Fill them completely.
After you're done with the sweetened condensed milk, add the caramel over the top of the cake.
Let the cake cool completely. Once it has, spread the whipped topping on it. Make sure to keep the layer as even as possible.
Sprinkle the Heath bar toffee bits on the whipped topping.
For the true chocoholic, drizzle the cake with chocolate syrup.
Portion the cake as desired and watch it vanish!