Preheat oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
In a stand mixer, cream butter and sugar on medium speed until light and fluffy, about 3-4 minutes.
Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
Alternately add dry ingredients and buttermilk to the mixer, beginning and ending with dry ingredients. Mix on low speed until just combined.
Fold in sour cream or Greek yogurt until smooth and homogeneous.
Divide batter between prepared pans. Bake for 22-25 minutes, or until a toothpick inserted in the center comes out clean.
Let cakes cool in pans for 10 minutes before transferring to a wire rack to cool completely.