Cut the plums into quarters and remove the stones. Tip the sugar into a pan with 225ml water, the cinnamon and vanilla. Gently heat until the sugar dissolves. Slide the fruit into the syrup. Bring the pan to the boil, then let it simmer for 5-10 mins, depending on the ripeness, until the plums are soft. Leave to cool slightly and serve as they are with something creamy.
Use your poached plums in brûléesTo make brûlées with the plums, strain and pour all the liquid back into the pan. Reduce the liquid by half until very sweet and sticky. Fill 6 ramekins two-thirds with plums, and add 1 tbsp of syrup. Wait for this to cool, then fill with mascarpone (a 250g pot will do it). Smooth the surface with a knife and refrigerate for 4 hours. To serve, heat the grill to high. Sprinkle golden caster sugar over the top and place under the grill until it caramelises. Leave to harden for a minute.