preheat the oven to 350 degrees F and line three 6-inch pans with parchment paper. in a large bowl, combine the cake flour, sugar, baking powder, baking soda and salt and whisk together. in another bowl, combine the oil, eggs, egg whites, vanilla bean, vanilla, and milk and whisk together. pour the wet ingredients into the dry and mix until fully combined. place the batter in the pan and bake for 20-25 minutes or until a toothpick comes out clean. let the cake cool for 10 minutes then carefully remove them from the pans to continue cooling. wrap in cling wrap until ready to use.