For the chocolate truffles, boil whipping cream together with glucose. Add the dark chocolate coating in pieces and dissolve while stirring constantly.
Remove the saucepan with the mixture from the heat and stir in the butter. Drizzle in the rum.
Allow the mixture to cool, whisking constantly until the praline mixture reaches a creamy consistency.
Fill the mixture into the hollow balls using a piping bag. Place the balls in the refrigerator and allow the dark chocolate to dissolve.
Melt a small part of the semi-sweet chocolate coating, pour it into a bottle for sugar decoration and close the balls with it. Put the balls back in the refrigerator.
Melt the rest of the couverture and pull the balls through the chocolate using a praline fork.
Roll chocolates back and forth on a draining rack to create the typical “hedgehog” pattern. Place on buttered paper and store the chocolate truffles in a cool place.
If you like, you can also make white chocolate truffles.