Preheat oven to 180 and prepare donuts mould
Mix flour, baking soda, 1/3 cup sugar, cocoa powder and cinnamon in a bowl
In seperate bowl, whisk egg, buttermilk, melted butter and 2 teaspoon vanilla extract
Add vinegar and red food colouring. Mix well
Gradually add dry ingredients and mix well
Add batter to donuts mould filling 3/4 level. Bake for 10-11 minutes until lightly firm to touch
Allow to cool for 30 minutes
Demould and cool completely on wire rack
In a bowl, whisk creamcheese, milk, powdered sugar and vanilla extract
Dip donuts in creamcheese frosting. Set aside for 15 minutes
Serve