Preheat oven to 350F. Prepare a square pan.
Combine all of the dry ingredients in the bowl of a KitchenAid (paddle attachment). Mix for a minute to air the cake flour.
Add pieces of cold butter until the mixture is crumbly in texture. Add emulsion to buttermilk, and add half of the mixture to the egg whites.
Pour the emulsion into the batter, mix to combine, and add the egg whites. Beat for a minute.
Bake for 25min. Let cool in the pan before removing.