To make caramel filling, Place can, fully submerged in water, in slow cooker. Turn on high. Cook for 4 hrs. Allow to fully cool (I preferred overnight)
Make muffins as per Gluten Free Chocloate cake method States.
Once muffins are cooled, pipe desired amount of caramel into the centre of the muffin. Complete by icing muffins and put in fridge to help set caramel and icing.