Preheat oven to 350°F. Lightly grease a 12-count donut pan with non-stick cooking spray. Set aside.
In a large bowl, beat butter, sugar, vanilla extract, and food coloring with a stand mixer with fitted paddle attachment or hand mixer. Mix in egg until combined. Set aside.
In a medium bowl, whisk flour, cocoa powder, baking powder, baking soda, and salt.
Slow add half of flour mixture into wet mixture and combine. Pour in buttermilk, vinegar, and rest of flour mixture. Mix to combine.
Pour mixture into a large ziplock bag and cut tip of bottom corner. Pipe mixture into prepared donut pan.
Bake 10-12 minutes or until slightly firm. Remove from oven and cool completely before frosting.
To make the frosting:
To prepare the cream cheese frosting, cream together butter and cream cheese in a medium bowl until combined. Add in powdered sugar and vanilla and stir well.
Spread over cooled donuts using a spatula or knife.