A French student of mine was kind enough to share the recipe for one of her children's favourite cakes that I am thrilled to share with you. I have many French students and I love speaking to them and learning about all the cultural nuances.
Method Prep:25min › Extra time:12hr setting › Ready in:12hr25min
Melt the chocolate with the butter in Bain Marie (in a bowl over gently simmering water). Allow it to cool for 5 minutes and then add the egg and icing sugar and mix vigorously (so that the egg doesn't set).
Crush the biscuits roughly by putting them in a bag and crushing with a rolling pin. Cut the marshmallows into small pieces (about the size of a tiny coin). Combine with the chocolate mixture.
Cut a large piece of cling film and lay it on your work surface. Pour the mixture onto the cling film and roll it tightly into a log.
Place the rolled mixture onto a sheet of foil and secure it tightly. Place in the fridge for 12 hours.
After 12 hours, remove the foil and cling film, and sprinkle with some extra icing sugar. Cut into slices and enjoy!