Preheat your oven to 220C / 425F / Gas mark 7.
Lightly grease or line your muffin pan with cases.
In a large bowl sieve the cocoa, flour, baking powder, salt and cinnamon together. If you don't own a sieve mix them well into each other. Then add in the chocolate chips and make sure they are well distributed.
In another medium bowl add the eggs and sugar and either whisk or beat them together until lighter in colour.
Add in the buttermilk, vanilla extract and vegetable oil into the egg mix and whisk again until everything is well combined.
Add the red food colouring to the liquid ingredients and stir it in.
Pour the red egg mix into the large bowl with the flour mix in it and very gently combine the two. Don't over mix this batter otherwise it will make your muffins tough.
You want everything to be just combined, it's okay to have a lumpy looking mixture.
Spoon the mixture into your prepared muffin pan. Fill those cups right to the top, otherwise you won't get that lovely high dome.
Pop the filled pan into your oven.
After 5 minutes you need to turn your oven down to 190C / 375F / Gas mark 5. The higher heat will have allowed your muffins to dome and now they need to bake all the way through. If left at the higher temperature they would burn.
Bake for a further 13-15 minutes. You want them to be firm to the touch and a tooth pick to come out clean after being inserted.
Leave them in their tins for 5 minutes to slightly cool. Then transfer them to a wire rack to fully cool down.
Like most muffins they taste best on the day of baking, but will keep in an airtight tin for up to 4 days.