In a sauce pan heat one cup of cream and the cocoa powder together while continuously whisky whisking. Once it reaches a boil, turn down the heat to medium and let it simmer for 30 seconds.
Take this off the heat and add in the chocolate and mix while scraping the bottom.
Once combined, add in the other 1 cup of cream and combine.
Then shift this to a separate bowl and place a sieve over it. Scraping the pan as much as possible.
In the same pan heat together, the milk, sugar and salt.
In a separate bowl whisk the egg yolks.
Once the mixture is heated properly, slowly add it to the yolks while constantly whisking them.
Then shift this mixture back to the pan and keep stirring constantly till the mixture coats the back of your spoon (wooden spoon).
Then pass this mixture through the sieve and into the chocolate mixture you made earlier.
Add In The vanilla essence and stir.
Once combined, place the bowl in an ice bath and stir till it cools.
Refrigerate for two hours and then put in your ice cream machine according to the instructions on it.
If you do not have an ice cream churner, just place the cooled mixture in the freezer and whisk it after every two hours ( do this three times ) and then let it set till it sets.