Preheat your oven to 160 fan and line 3 x 6 inch round tins with baking paper. I use fry light cooking spray to spray around the inside of the tin and pop a precut 6 inch round on the bottom. (Precut liners makes life so much easier)
Mix together on high the butter, sugar and vanilla for a few minutes util lighter in colour and fluffy.
Add in all the other ingredients together and mix until combined. This is the black cocoa powder I use and it was amazing!!!.
Cook in a preheated oven at 160 fan for around 25-30 minutes or until cooked.
The cake is cooked when a skewer inserted in the middle comes out clean.
Leave to cool for 10 minutes before turning out from the tin and cool completely before decorating.
Soften the butter in the microwave and them mix on high for 3-4 minutes until pale and fluffy. Add in the icing sugar and vanilla and mix again for 3-4 minutes.
Add in 1-2tsp boiling water until it is at the correct consistency and then add in the food colouring to suit.
Pop in a piping bag. NO nozzle is needed. Just snip the end off to a 1cm opening. Now pipe around each layer of cake as you stack the cakes together. Finish off with sprinkles.