For the Limoncello truffles, chop the chocolates. Bring the cream to the boil in a saucepan, remove from the heat and add the chopped chocolate. Stir until the chocolate has dissolved and a homogeneous mass has formed.
Mix the room-warm butter with the powdered sugar until smooth, then stir in the limoncello. Stir in the chocolate mixture by the spoonful. Cover and refrigerate for about 40 minutes, the mixture should be viscous when further processed.
Line a baking tray with baking paper. Place chocolate mixture in a piping bag fitted with a medium hole nozzle and pipe 60 dots, spaced apart, onto the baking paper. Chill for at least 2 hours. Roll the chocolate-limoncello mixture into balls with your hands and chill until ready to dip.
Prepare the chocolate coating for the dunking mixture or use pre-made dunking mixture from a specialty store. Dip the cooled Limoncello truffles into the chocolate coating using a chocolate tongs, carefully wipe the coated truffles off the edge of the bowl to avoid “feet”, and let them dry slightly on a draining rack. Then roll back and forth on the draining rack to create the typical praline pattern. Allow the Limoncello truffles to cool, store in a cool place and consume within 2 weeks.