Mix all the dry ingredients in a large bowl with a whisk.
To the dry ingredients add the shortening, milk, water, and vanilla.
Beat the batter with a mixer for 2 minutes.
Scrape the bowl and mix for 2 minutes more.
Grease a muffin tin or line with muffin liners and fill ⅔ full with cake batter.
Bake at 350 degrees for 30 minutes or until fully baked.
Cool before frosting.