Place 100gm sugar and 1½ tbsp water in a small saucepan and cook over medium heat, tilting saucepan, for 5 minutes or until sugar dissolves and becomes golden. Do not stir. Remove from heat, then immediately divide among six 125 ml ramekins, tilting to spread evenly over base and up sides.
Soak gelatine leaves in cold water for 5 minutes or until softened, then squeeze out excess water.
Place cream, remaining sugar, scraped seeds from vanilla bean and bean in a saucepan and stir over low heat until sugar dissolves, then bring to the boil over medium heat and simmer for 1-2 minutes. Remove from heat, then add softened gelatine to pan and stir until gelatine dissolves. Remove vanilla bean. Divide cream mixture among ramekins, cool to room temperature, then refrigerate overnight or until set.
To serve, run a knife around inner edge of ramekins, then turn out onto plates and serve immediately.