Butter the bottom and sides of an 8" x 3" round cake pan, Line the bottom with parchment paper and butter the paper. Coat the bottom and sides with flour.
Preheat your oven to 350℉.
In a small bowl combine the all purpose flour, cake flour, baking powder and salt. Set aside.
Combine the milk and butter and heat until the butter is melted and the mixture reaches a temperature of 140℉.
In the bowl of an electric stand mixer, or a large bowl if using a hand mixer, place the sugar and eggs. Using the whisk attachment beat for 3-4 minutes until lighter in color and about tripled in volume.
Sift the dry ingredients into the egg/sugar mixture and beat on low until everything is combined.
With the mixer running on low spead, gradually add the hot milk/butter and mix until combined.
Scrape the bottom and sides with a rubber spatula to insure that ll the ingredients are combined.
Pour the batter into the prepared pan and bake for 20-22 minutes or until the top is a light golden brown and the top springs bal when gently pressed.
Remove the cake from the oven and place the pan on a rack to cool.
Next, remove the cake from the pan and place on a serving plate.