Preheat the oven to 160 fan and grease and line 2 x 20cm spring form cake tins.
Chuck the flour, cocoa powder, baking powder, bicarbonate of soda, golden caster sugar into a large mixing bowl. Mix and then add the eggs, milk, vegetable oil, a pinch of salt and water. Mix until incorporated. Don't be alarmed, it will be very runny.
Divide the mixture between the two cake tins and bake for 30-35 minutes or until a skewer comes out almost clean from the centre. Leave to cool for 10 minutes and then remove from the tins and cool completely.
To the make the buttercream, melt the chocolate and then set to one side to cool completely. Beat the butter for 3-5 minutes until pale. Add ½ the icing sugar and beat until combined. Add the remaining sugar, coco powder, milk and chocolate and whisk until smooth.
Place one of the cakes onto a stand and spread over half the buttercream. Place the other cake over the top and cover with the remaining buttercream. Smooth out and serve immediately.
O
