Put everything except the vanilla in a pot and bring it to a boil, then turn down to a simmer. Continue cooking until it looks like it is broken and separating; this will take about 30 minutes. Take it off the heat, whisk in the vanilla, and then blend it with a hand blender to smooth it out. Chill until ready to serve then heat it up.
Pour over scoops of ice cream, topped with whipped cream, and chopped peanuts.
Recipe courtesy of Gale Gand