Preheat your oven to 325°F (165°C). Grease and flour two 9-inch round cake pans, then line the bottoms with parchment paper circles.
In a bowl, sift together the all-purpose flour, cake flour, baking soda, baking powder, salt, and sugar. Set aside.
In the bowl of an electric mixer, beat the vegetable oil, shortening, and clear vanilla extract until light and fluffy using the whisk attachment on high speed.
Beat in the eggs one at a time, mixing well after each addition.
Fold in the dry ingredients alternately with the buttermilk, being careful not to overmix; stop as soon as the batter is smooth.
Pour the batter evenly into the prepared cake pans.
Bake for 30-35 minutes or until a wooden toothpick inserted in the center comes out clean.
Let the cakes cool in the pans for 10 minutes before transferring them to wire racks to cool completely.
Notes
This cake pairs well with Marshmallow Frosting or any vanilla frosting of your choice.