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.