Melt the chocolate in a water bath, if necessary (if it is liquid, there is no need). In a large bowl put the milk, liqueur, chocolate and cocoa. Beat them carefully on low speed mixer. Then slowly increase the speed until the mixture initial rising. Crush the biscuits into small pieces. Then prepare the glasses, which will serve dessert. They can have wine, ice cream or similar, but with mandatory seat more elegance. Put the bottom about 30 g of the resulting chocolate mousse, 2 tsp of crushed biscuits and 2 tbsp of chocolate topping. Repeat once in each glass by reducing the amount of the biscuit crumbs in half. Refrigerate for about 2 hours and serve as the top decorate with cream roses.