Preheat the oven to 325°F. Grease and flour a 10-inch tube pan or Bundt pan.
In a large mixing bowl, cream together the softened butter and sugar until light and fluffy.
Add the eggs one at a time, beating well after each addition.
In a separate bowl, whisk together the flour, baking powder, and salt.
Alternately add the dry ingredients and sour cream to the creamed mixture, starting and ending with the flour mixture. Stir in the vanilla extract.
Pour the batter into the prepared pan. Bake in the preheated oven for about 60-70 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely.