Pre Heat oven to 350°F/176°C
With a stand mixer or hand mixer cream together butter and sugar until pale and yellow, about 3 minutes.
Add in your eggs, beat until light and fluffy, about 2-3 minutes.
Sift your cocoa powder in, sifting is very important with the cocoa powder, it will be lumpy if you don't sift.
Mix in the sour cream, buttermilk, vanilla and red food coloring, the mixture may look a bit curdled at this point, it is normal.
Add in the cake flour, baking soda, and salt. Mix until just combined, do not over mix!
If you are making cupcakes, divide the batter into cupcake liners and fill 3/4 of the way full. If you are making a round cake, divide the batter evenly between 2 greased 9" rounds.
Bake cupcakes for 15-20 minutes, until a toothpick inserted in the middle of the cupcake comes out clean. For a 9" round bake for 25-30 minutes, or until a toothpick inserted in the middle of the cake comes out clean.
Allow cake to cool completely and top with your favorite frosting!