Warm the cream, sugar, vanilla, and vanilla seeds in a small saucepan over medium heat until the sugar is dissolved. Be sure that all the sugar is dissolved; you will no longer feel any grittiness from the sugar when you rub some cream between your fingers. Strain into a bowl, cover, and chill well.
Add the Armagnac and freeze the mixture in an ice cream freezer according to the manufacturer's directions. Spoon into a freezer container and allow to chill in the freezer for a few hours before serving.
Copyright The Barefoot Contessa Parties! by Ina Garten (Clarkson Potter, 2001)