1. Preheat oven to 200C. Put the gem irons in the oven.
2. Beat the first measure of butter with the sugar until pale. Beat in the egg and then the golden syrup. Fold in the feijoas.
3. Sift the flour into the mixture and fold in with the desiccated coconut.
4. Stir the baking soda into the warm coconut milk then quickly stir into the mixture.
5. Divide the second measure of butter into 12. Remove the gem iron from the oven and drop in the pieces of butter, then spoon in the mixture. Bake for 10 minutes or until well risen and golden.