Honey Cinnamon Buttercream White Cake

1. Mix the cake flour, sugar, baking powder, baking soda, and salt together until combined.
2. Cut the butter into medium size cubes and add to the dry ingredients.
3. Mix on low speed until the mixture is combined and crumbly.
4. Add half of the buttermilk to the mixer and turn the speed up to medium and mix for a full minute.
5. Combine the rest of the buttermilk with the egg whites and vanilla and add in three additions while the mixer is running. Wait until each addition is fully incorporated before adding the next.
6. Divide between 2 9-in cake pans that have been greased and lined with a parchment paper circle.
7. Bake at 350F (177C) for 30-35 minutes or until a toothpick inserted in the center comes out with a few wet crumbs.