Bring the whipping cream, margarine, honey and coffee powder to the boil and remove from the heat. Chop both types of chocolate and dissolve in the whipped cream. Flavor with coffee liqueur. Allow the mixture to cool (maximum 28-30°C), fill into a piping bag with a nozzle and pipe into the chocolate shells. Leave the truffles to cool overnight. Melt dark chocolate and let cool well. Pour into a stanizel and seal the top of the truffles with it. Refrigerate for 1 hour. Then, using a fork, pull the truffles through the remaining tempered chocolate. Place on a glazing grid. Place on a baking sheet lined with parchment paper and allow to set. Sprinkle with cocoa.