Melt together the dark chocolate & salt with the milk alternative in a dish over a pan of water.
Mix together well then add the everything except the gluten free flour, mixing together thoroughly for around 20 seconds.
Once you have a paste like substance mix in the gluten free flour. Line the baking tray with grease proof paper and scrape in the brownie batter. Bake at160c in a pre heated oven for 40 minutes, turning half way.
Remove from the oven and allow to cool and refrigerate over night.