Pre heat the oven to 180°C and grease and line a 20cm circular cake tin.
Add your cocoa powder, caster sugar and melted dairy free butter to a bowl and mix until combined.
In a separate bowl beat your 3 eggs. Gradually add the beaten eggs to the chocolate mixture and stir well.
Next, add your gluten free flour and xanthan gum to the mixture and stir until fully combined.
Stir through your chunks of chocolate and then pour the mixture into your cake tin.
Bake for around 30-40 minutes (See notes for more details on baking times).
Remove from the oven and leave to cool in the tin. I prefer to leave my brownies in the fridge for a couple of hours before removing and cutting. The fridge helps the brownies become even more fudgy and delicious.