Preheat the oven to 350 degrees. Line two baking tins with paper liners and set aside.
Whisk together the flour, baking powder, and baking soda. Set aside.
Add the butter and sugar in a mixing bowl, or a bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed for 3 to 5 minutes, or until light and fluffy.
Add the eggs, one at a time, stirring until each is incorporated.
Scrape the sides of the bowl. Stir in the vanilla and sour cream.
Add the dry ingredients and buttermilk, alternating between the two until fully incorporated.
Fill the cupcake liners 2/3 full. Bake 15 to 17 minutes, or until a toothpick comes out clean.
Cool and top with your favorite frosting.