Preheat the oven to 180C. Grease and line a 9″ springform cake tin.
In a heat proof bowl combine, butter, sugar, chocolate, coconut oil, water and coffee. Heat in the microwave on high for 2 minutes or until the butter has melted.
Stir the ingredients until it it all comes together.
In a separate bowl combine the besan flour, cocoa powder and the baking powder and give a light whisk to evenly disperse ingredients. (If the besan has some lumps feel free to sift it, but just for the record I never do at home)
make a well in the dry ingredients, pour 1/3 of the wet mix in and stir until combined, then add the remaining wet ingredients in 2 batches stirring to combine after each addition.
Add the eggs to the batter and stir until just mixed in.
Pour into lined baking tin and place in the preheated oven.
Bake for approx 1 hour or until the top of the cake it a slightly bouncy. If you do the skewer test the cake should still be a little sticky but cooked.
Leave in the tin to cool slightly then remove and cool to room temperature before wrapping and placing in the fridge. Leave for at least 4 hours or overnight.