Place sugar in a heavy saucepan over medium heat. Cook, stirring constantly with a wooden spoon, until sugar melts and becomes golden brown. Remove from heat; gradually add hot water, stirring constantly. Return to low heat; cook, stirring constantly, until syrup reaches thread stage (230°). Remove from heat.
Beat egg yolks; gradually pour syrup into egg yolks, beating constantly. Beat egg whites (at room temperature) in a medium mixing bowl until foamy. Gradually pour syrup mixture into egg whites, beating until cool. Chill. Stir in vanilla.
Beat whipping cream in a large bowl until soft peaks form. Fold chilled syrup mixture into whipped cream ; fold in almonds. Spoon into an 8 - inch square pan; freeze until firm. Scoop into individual serving dishes, and serve.