For the chocolate sauce: Melt the chocolate chips in the microwave for 30 seconds. Add whipping cream. Mix well.
In a pot, combine milk, cacao powder, ginger slices, cinnamon and a star anise. Cook and stir over low heat until fragrant, occasionally whisk to avoid burning the chocolate. Turn off the heat before it comes to a boil. Add the chocolate chips and whipping cream. Mix well. Let it cool down to desired temperature before serving.
Line the glass with the chocolate sauce. Add the hot chocolate, top it up with some marshamallow and cacao powder, or any toppings of choice. Dizzle some chocolate sauce on top and enjoy!