Wash and stone the plums. Dice the flesh, weigh 1.5 kg. Halve lemon, squeeze juice. Mix plums with jam sugar and lemon juice. Let stand for about 30 minutes.
In the meantime, roast the almonds in a pan without fat until golden brown. Let them cool down on a flat plate. Bring plums, almonds and cinnamon sticks to the boil in a large saucepan. Let it boil fizzy for 3-4 minutes while stirring. Stir in liqueur. Fill jam into 6-7 prepared sterile jars with twist-off cap and close them immediately. Leave to stand on the lid for about 5 minutes. Turn over and let cool down
Waiting time approx. 25 minutes