Preheat your oven to 170ºC/150ºC Fan, and line two 6" deep cake tins with parchment paper.
Add the unsalted butter and light brown soft sugar to a bowl, and beat until light and fluffy.
Add in the self raising flour, cocoa powder, eggs and peppermint extract and beat again until a lovely smooth cake mixture is formed.
Split evenly between the two tins and bake in the oven for 35-45 minutes (or until a skewer comes out clean!)
Once baked, leave to cool in the tin for 10 minutes, and then leave to cool fully on a wire rack.
Buttercream
Beat the unsalted butter on its own for a while in your mixer until its smooth and supple.
Add in your icing sugar a little at a time and beat fully until its light and fluffy and add the peppermint extract!
(If the mixture is really stiff, add in 1-2tbsp of boiling water and beat fully to smooth out)
Add a jumbo round piping tip to a large piping bag, and carefully brush a small amount of buttercream up the sides of the piping bag in stripes. I use a 5mm brush, and do four stripes.
Add the buttercream to the piping bag.
Decoration
Level the cakes off if necessary. Split the two cakes into two so you have four layers in total
Add your first cake to a cake board or flat serving plate and secure with a small amount of buttercream.
Pipe round of buttercream onto the first layer, add the second layer, and repeat with the buttercream. Repeat with all layers.
On the final layer, add some extra buttercream, and add some sprinkles and candy canes.
Notes
This cake will last 3-4 days once made, at room temp.
The flavouring can be swapped for any flavour you fancy, and the decoration is completely optional.
If you want to make an 8" cake, use a 500g mix (400g flour/100g cocoa) and bake for 50-60 minutes. Use 1/3-1/2 more buttercream.