Place all of the ingredients for your cake together in your mixing bowl.
Mix these together until the ingredients are fully combined. This usually takes around 30 seconds.
Divide your mixture between 2 x 6 inch cake tins. I like to cover the inside of my tins in a thin layer of butter and dust with flour, before adding a circle of parchment to the bottom to stop the mixture from sticking.
You then want to bake your cakes for around 45 minutes on the middle shelf at 180 degrees Celsius. For my oven I use a normal oven setting. I don't actually use my fan oven when baking cakes as it tends to bake the cakes quicker on the outside so you get this hard crusty shell and the mixture is not baked all the way through.
After 45 minutes you can take a cocktail stick or bamboo skewer and push this into the center of the cake. If it comes out clean you know your cake is baked all the way through. You can then place your tins of a wire rack to let cool for a few minutes before turning them out, and allowing to fully cool.
Whilst the cake is cooling you will need to sift your icing sugar into your mixing bowl. To this add the butter, flavouring, and milk.
Then mix your buttercream on a medium speed. After around 5 minutes your buttercream will start to go creamy. You can then add any gel colouring depending on the theme of your cake.
Once your cake has cooled you can level off the top and divide each layer into 2. Placing your buttercream between your layers, stack your cake.
You then want to add a thin crumb coat of buttercream around the edge of your cake to lock in any loose crumbs. Place your cake into the fridge for around 30 minutes to allow the buttercream to firm up.
You can then go in with the rest of your buttercream, adding a nice finish around the side of your cakes. This is then ready for any final decorations.