Wash plums, halve, stone and cut into thin slices. Bring malt beer and half the cane sugar to the boil. Stir starch in a little cold water until smooth and add to the boiling malt beer.
Bring to the boil again briefly. Add plums, except for 12 slices for garnishing, to the compote and leave to cool. Beat cream cheese, yoghurt, icing sugar and lemon juice with the whisk of the hand mixer until foamy.
Layer compote and cream in 4 dessert glasses. Garnish with remaining cane sugar, remaining plum wedges and lemon balm leaves.