In another vessel blend /mix butter and brown sugar with an electric mixer till its fluffy.
Then start adding egg one after the other as beat To this add the flour mix which was sifted in step 1.Make sure to add one part of flour and mix ,then 2 parts of buttermilk and mix till all the ingredients have been mixed well.
Now take a cupcake tray having 8 or 10 cupcake holders .Place paper liners in each holder and pour the batter equally up to 3/4t of each paper liner.
Preheat oven to 350 degree Fahrenheit and place the tray in it. After 8 mins rotate the tray and bake another 8 or 9 mins till. After it is baked cool it and its ready with frosting on top.
To make the frosting blend the unsalted butter and cream cheese til lit becomes fluffy.
Slowly keep adding vanilla extract and sugar till he mixture becomes smooth.
Put this frosting in the decorating tools/dispenser and decorate.