Hot liquid (4 cups heavy cream + 2 cups milk, divided into 3 equal parts, 2 cups each for 3 different chocolate layers, needs to be kept hot or reheated and poured over the different kinds of chocolate. You do need to wait for each layer to set in the fridge for at least 30 minutes, before you carefully add the next layer). Some readers have reported that the dark and milk chocolate layers may turn very similar in color. We want them to be different! Since the dark chocolate layer is prepared last, feel free to add 1 tbsp dark cocoa powder + 1 tbsp sugar to the layer, in cake it looks similar in color to the milk chocolate.