Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.

Add eggs one at a time to the butter mixture, ensuring full incorporation before adding the next egg.

In a separate bowl, mix the dry ingredients together: all-purpose flour, cocoa powder, baking soda, baking powder, and salt.

Alternately add the dry and wet ingredients (buttermilk, sour cream, and vanilla) to the butter mixture, beginning and ending with the dry ingredients. Mix gently until just combined.

Pour the batter evenly into the prepared cake pans and smooth the tops.

Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.

Let the cakes cool in the pans for about 10 minutes, then remove from the pans and transfer to a wire rack to cool completely.

Frost with your favorite frosting once completely cool. Enjoy the cake as a delightful treat!