In a very small saucepan sprinkle gelatin over water and let stand about 1 minute to soften. Heat gelatin mixture over low heat until gelatin is dissolved and remove pan from heat.

In a large saucepan bring cream, half and half, and sugar just to a boil over moderately high heat, stirring. Remove pan from heat and stir in gelatin mixture and vanilla. Divide cream mixture among eight 1/2-cup ramekins and cool to room temperature. Chill ramekins, covered, at least 4 hours or overnight.

Dip ramekins, 1 at a time, into a bowl of hot water 3 seconds. Run a thin knife around edge of each ramekin and invert ramekin onto center of a small plate.