Preheat oven to 350°F. Line a standard muffin/cupcake pan with liners. On medium-high speed, cream butter and sugar until light and fluffy, about 3 minutes. Turn mixer to high and add the egg. Scrape down bowl and beat until well incorporated.

In a separate small bowl, mix together cocoa powder, vanilla and red food coloring to make a thick paste. Add to batter and mix on medium until completely combined. Reduce speed to low and slowly add half of buttermilk. Add half of flour and mix until combined. Scrape bowl and repeat process with remaining milk and flour. Beat on high until smooth. Again, reduce mixer speed to low and add salt, baking soda and vinegar. Turn to high and beat for another couple of minutes until completely combined and smooth.

Divide batter evenly between cupcake liners and bake 20 minutes, until a toothpick inserted in center comes out clean. Cool 10 minutes and remove cupcakes from pan and place on rack to cool before frosting.

Frosting  Using whisk attachment, whip butter and cream cheese on high speed about 5 minutes, scraping bowl as necessary. Reduce speed to low and slowly add powdered sugar until all is incorporated. Add vanilla and mix to combine. Increase speed to medium high and whip for a few minutes until frosting is light and fluffy, scraping bowl as necessary.