Preheat the oven to 350°.
Line a cupcake pan with 6 liners.
In a large mixing bowl, beat the butter with sugar, then add in the egg and mix well on low-medium speed. (or use a whisk to hand mix as I do)
Add in the flour with baking powder, baking soda.
Begin to mix and add in the buttermilk and vanilla until completely combine on low- medium speed.
Portion out the batter with a 3 tablespoon scoop into each cupcake portion.
Bake at 350° for 18 minutes or until a toothpick comes out clean.
Allow cupcakes to cool for 10 minutes in the pan, then remove the cupcakes and allow them to cool on a cooling rack.
Allow cupcakes to cool completely before frosting them.