Preheat oven to 325 F. Grease and flour a bundt pan and set aside.
In a large bowl sift together flour, baking powder and salt. Set aside.
In a large bowl, cream together butter and sugar just until creamy on low speed.
Mix in eggs one at a time.
Mix in vanilla extract.
Add dry ingredients to wet ingredients, alternating with the buttermilk. (Be sure to mix on low JUST until combined. Overdoing it will result in a cake with streaks)
Mix until batter is well combined and fluffy.
Mix in sour cream just until combined.
Spoon batter into prepared pan.
Bake on middle rack for 90 minutes.
Remove from oven and let cake sit in pan until pan is warm.
Remove cake from pan and place on a cooling rack to finish cooling.
Serve plain or topped with berries and fresh cream!