Preheat oven to 160°c. Grease and line two 20cm cake tins.
Place butter, chocolate, brown sugar, water, golden syrup and vanilla in a saucepan. Stir over medium heat until chocolate melts and mixture is smooth. Remove from heat and cool for 20 minutes
Add eggs one at a time, beating well after each addition.
Mix flours and whisk together thoroughly or sift to combine.
Stir flours into chocolate mixture and mix with a wooden spoon until well combined.
Pour mixture into the prepared cake tins and bake for 50 minutes and check with a skewer. If not cooked return for 5 minutes and test again. I found that I had to cook for a total of 60 minutes but it will depend on your oven.
Leave cakes in the tins to cool for 5 minutes and then remove and cool on a wire rack until cool and then they are ready to decorate.
