Use a food processor to powder the biscuits or you can also seal them in a ziplock bag and crush using a rolling pin. Take a dry bowl and add in the powdered biscuits. Stir in melted butter, cocoa powder and mix it well.
Take a cupcake pan and grease it with butter or oil. Add in the biscuit mixture and make a small dent in the middle. Bake for 10-12 minutes at 150 degree centigrade until the colour of biscuit mixture changes and they become hard.
After taking the pan out of the oven, put a piece of chocolate inside the dent, then keep a marshmallow on top of it while it's still hot.
The heat from the pan will cause the chocolate and marshmallow to melt beautifully. After they cool down a bit, garnish with chocolate shavings or chocolate chips as desired.
