Take the butter out to soften.Whip it with the sugar. Add the eggs one by one.
Melt the chocolate in a bain-marie or in the microwave.
Pour it into the mixture. Mix well.
Add the flour, baking powder and pinch of salt. .
Then add the milk until you have a smooth batter.
Pour the batter into the tin and bake for 20 minutes.
Meanwhile, prick marshmallows on toothpicks.
Roll out the sugarpaste and use a cookie cutter to form circles.
Prick the toothpick with the marshmallow into the cupcake. Place the disc of sugar paste on top to create the shape of a ghost. Draw eyes and a mouth using melted chocolate.