Cook rice according to package directions. Rinse in cold water; drain. Cover and refrigerate. In a bowl, beat cream until soft peaks form. Gradually add sugar and vanilla, beating until stiff peaks form. Fold into the rice. Cover and refrigerate.
In a large saucepan, combine the sugar, salt, cream and corn syrup. Cook over medium heat until a thermometer reads 238° (soft-ball stage), stirring frequently. Remove from the heat; carefully stir in butter and vanilla. Cool slightly. Serve warm sauce over rice.