Preheat oven to 350 degrees
In a large bowl, cream together butter and sugar. Once light and fluffy add your pink food coloring. Start with a small amount and increase to reach your desired shade of pink. Blend well with butter and sugar.
Add in eggs, one at a time, beating well after each addition. Add in vanilla and beat well.
Combine the flour, baking powder, baking soda and salt in a separate bowl. Add 1/3 of the dry ingredients to the batter and beat until well combined. Add in 1/2 of the butter milk, beat until combined, followed by another 1/3 of the dry, then the remaining buttermilk and finally the remaining dry ingredients. The batter may look a bit lumpy after buttermilk is first added, but beat well and it will combine nicely.
Fill paper lined muffin cups two-thirds full and bake at 350 degrees for approx 20-25 minutes or until a toothpick inserted into the center comes out clean. Watch the cupcakes closely in the last few minutes of baking so that they do not over brown. Allow to cool for ten minutes before removing from pan, then transfer to a wire rack to finish cooling.