In a large mixing bowl, sift the flour and cocoa powder together. Add in the sugar, baking powder, baking soda and salt. Mix. In a separate mixing bowl, mix the oil, vanilla, eggs, and buttermilk.
¾ cup Dutch process cocoa powder, 1 ¾ cup White granulated sugar, 2 teaspoon Baking powder, 1 teaspoon Baking soda, 1 teaspoon Salt, ½ cup Oil, 1 teaspoon Pure vanilla extract, 3 Large eggs, 1 cup Buttermilk