Use ingredients at room temperature when making the cake. The reason for this is simple: ingredients all at room temperature will combine better and make for a better bake! So this means the butter, eggs and milk should all be at room temperature before you start any mixing.
Beat the butter well at the start of making the cake. You want it light and smooth and pale for the best results.
Add the beaten eggs a little at a time to the butter mix. If you feel the mixture looks curdled at any point, simply add in a tablespoon of flour and mix through, then continue gradually adding in the eggs.
Fold the dry ingredients into the cake rather than beating them in. This is to prevent over working the gluten, which will result in a tough cake texture.
If you can't find self raising flour where you live, you can substitute for plain (all purpose) flour with a little extra baking powder too. If using plain flour, use same amount of flour as per the recipe, but add an extra 2 tsp of baking powder to the mix.
When making buttercream, working with soft (not melted) butter is key. Beating it up until pale and light and then adding the rest of the ingredients is pure magic!
You can either pipe or spread on the buttercream. Try to create a little dam in the buttercream for the jam to sit in. This will help prevent it sliding out from within the cake, so you will always have all the jam waiting to be scoffed in the cake!
Enjoy this cake within 2-3 days of making it for it to be at its best.