For the raspberry jam, rinse the raspberries with cold water and carefully sort them. Puree with a blender and pass the raspberry puree through a sieve to remove the many seeds.
In a saucepan, bring raspberry puree to a boil with preserving sugar, citric acid and raspberry liqueur. Boil for 4 minutes until bubbling and test the jam. To do this, drip some of the jam onto a cold plate. If it sets, the jam is ready. If not, let the mixture boil a little longer.
In the meantime, finely chop the dark chocolate. Stir into the raspberry mixture. Pour the raspberry jam into prepared twist-off glasses. Drizzle a little alcohol over the top, light and seal immediately. Place with the lid down on a tea towel and let cool.