For the chocolate cake add all the ingredients into your mixing bowl together. If you have eggs on the larger side you may with to hold back a small amount of milk until you can see the consistency.
Either with a stand mixer or using a hand whisk combine all your ingredients. You are looking for a smooth mixer which is spreadable, but not too runny. If your mixer is quite thick you can add the rest of the milk.
Split your mixture between 2x 6 inch cake tins. I like to add butter around the edge of my tins and dust with flour before adding a 6 inch disc of parchment paper into the bottom, so my cake won’t stick. Once the mixture is added smooth it out on the top.
Add your tins onto the middle shelf of a preheated oven at 180°C or 356°F for around 45 minutes. I always use a normal oven setting as I find fan ovens can bake the outside of the cake quicker than the inside. If you only have a fan oven you will need to reduce the temperature and bake for longer.
Remove the cakes from the oven when you are able to push a cocktail stick into the center and it comes out clear.
Leave your cake to cool before dividing each cake into 2 layers to give you 4 layers in total.
For the buttercream add all the ingredients into a clean mixing bowl, making sure to sift the icing sugar to get rid of any lumps.
Mix the buttercream in your stand mixer or using a hand whisk for around 5 minutes until smooth and creamy.
Once you are happy with the consistency of your buttercream it is ready to use to fill the layers of your cake.