Arrange biscuits to cover the entire bottom of a baking tray. Sprinkle marshmallows, chocolate chips and peanuts over the biscuits.
In a small saucepan, cook the butter and brown sugar until dissolved. Remove from heat and add vanilla. Pour evenly over the ingredients on the baking tray. Bake for 10 to 12 minutes in the preheated oven. Store in the refrigerator for 3 days or the freezer for 1 month.