I have tried several recipes and this one seems to work out the best for texture, taste and shelf life. But I still would like it a bit more moist. What I do to fix this is pipe a filling into each and every cupcake. This mimics what we do with layer cakes anyway so I find it to be the best solution for my issue with dryness.
This mixing method I use to produce the moist, light and buttery cake is the two stage.
It is a bit different than most recipes in that you mix together the dry ingredients with the fat/butter before adding any of the liquid/milk and eggs. What this does is coat the flour particles with fat creating tenderness. Then you whip it up to add air cells and viola! You have a light and tender cake.
Starting with your ingredients:
For the best mixing have all your ingredients at room temperature especially the butter! Butter creams the best at 70 degrees F. I have added the vanilla to the milk since it is distributed better in fat.
Add the rest of the liquid ingredient in two parts, scraping in between each. The batter should look very smooth and creamy and slightly loose... not runny just a bit loose.
This cake will rise well so don't over fill the pans. I usually fill about 2/3 of the way.
You can see the nice the airy texture.