Beat the butter until it is a white cream. While beating, add the sugar little by little and then add one egg yolk at a time. Beat everything until the cream is homogeneous. Pass the Maria biscuits through coffee, one at a time. Place one in the centre and 6 biscuits around the middle, spread them with the cream. Make another layer of biscuits and smear the biscuits again, repeat the process until you finish the biscuits. When the biscuits are finished, cover the cake with the remaining cream and spread it all around. Decorate with the grated biscuit and the coffee beans. Take it to the fridge for 2 hours. After 2 hours it is ready to serve. Enjoy!