In a large saucepan, warm the butter, brown sugar and confectioners sugar over medium heat until the butter has melted and the sugar has dissolved.
Remove from heat and add the ice cream, vanilla extract and spices. Whisk together until ice cream has completely melted.
Pour into freezer-safe containers and store in the freezer for up to 6 months (the batter will not solidify). We packaged our hot buttered rum batter into these pint-sized freezer containers from Amazon.