in a large bowl sift together the flour, baking powder, salt, and cocoa powder.
in the bowl, beat the butter until soft (about 1-2 minutes). Add the sugar and beat until light and fluffy (about 2-3 minutes). Add the egg and beat until incorporated. Add the vanilla extract and beat.
in a measuring cup whisk the buttermilk with the red food coloring. With the mixer on low speed, alternately add the flour mixture and buttermilk to the butter mixture.
in a small cup combine the vinegar and baking soda. Allow the mixture to fizz and then quickly fold into the cake batter divide the batter evenly among the 12 muffin cups.Bake in the preheated oven for approximately 18 – 23 minutes, or until a toothpick inserted in the center of the cupcakes comes out clean.