In a saucepan place the rice, water, and salt and bring it to a boil. Cover with foil and turn down the heat. Cook until tender, then turn the heat off, and let sit 5 minutes to absorb all the moisture.
In a saucepan, heat the milk, sugar, rind, and vanilla bean (if using vanilla extract stir it in with the yogurt at the end) until simmering and sugar is dissolved. Meanwhile, sponge the gelatin in cold water. Add the gelatin to the hot liquid and stir to dissolve. Strain the mixture into a clean bowl over a ice bath. Allow it to cool for a few minutes and then stir in the yogurt. Chill over an ice bath until it starts to thicken. Fold in the whipped cream. Then fold in the rice and dried plums. Place in cups and chill in the refrigerator for 2 hours.