1.
Preheat your oven to 200c.
2.
Divide 1 tbsp of butter between 4 holes in your cupcake tray.
3.
Place in the oven for about 3 minutes so that the butter melts.
4.
Meanwhile, mix together the arrowroot, milk, egg, salt and 1/2 tbsp melted butter.
5.
Divide the mixture between the 4 holes with the hot butter and place immediately back in the oven.
6.
Cook for about 20 minutes or until they have risen out of the tray and look puffed up.