Preheat oven to 350° F. Line cupcake tins with paper cups. In a medium bowl combine the flour, Davis Baking Powder, baking soda and salt. Set aside. In a separate bowl, combine the vanilla extract and buttermilk. In a large bowl, cream the butter and sugar until fluffy. add the eggs one at a time and beat until combined. With the mixer on low speed, add the flour mixture in 2 equal portions, alternating with the buttermilk mixture, starting and ending with the flour mixture. Mix after each addition until JUST combined. Divide the batter evenly among the cupcake tins, filling each about 2/3 full. Bake the cupcakes for 20 – 30 minutes. To test for doneness, insert a toothpick in the middle of a few cupcakes at a time and remove. Take the cupcakes immediately from the oven in their pan to a wire cake rack and let them sit for 5 minutes before turning out onto the rack to cool right-side-up.