Put the chestnuts in a blender and puree finely with the rum and almond paste.add the vanilla sugar and taste the puree – add more sugar if needed.
Form hearts from the mixture and place in the freezer briefly to make them firm enough to coat.
Add cooking chocolate to boiling whipping cream, remove from heat and stir until chocolate is completely dissolved. Coat the hearts with it and let them dry, laid out on baking paper.