Preheat oven to 350°F.

In a stand mixer (using paddle attachment) or in a bowl (using a whisk to mix) add in your salted butter and granulated sugar, and cream together on medium speed.

In a separate bowl, add your cake flour, baking soda, and baking powder together.

Once your butter and sugar are creamed together, add in one egg at a time and mix on low speed until incorporated.

Once you have added all your eggs, add your egg whites into the mixture and mix on low speed until incorporated.

Add in your buttermilk and dry ingredients to the butter, sugar, and eggs mixture a little at a time, switching back and forth until you have added it all.

Lastly add your vanilla extract.

Butter your pans, then evenly distribute the batter into your pans and bake for 25-35 minutes or until toothpick comes out clean. (don’t go off of the time because depending on pan size and oven, the cooking time will vary).