Serves: Makes 10 portions1) Place the cocoa powder and 250ml single cream into a medium saucepan over medium heat and whisk to combine.
2) Add the remaining single cream and the double cream. Bring the mixture jto a simmer, stirring occasionally, and then remove from the heat.
3) In a medium mixing bowl whisk the egg yolks until they lighten in colour. Gradually add the sugar and whisk to combine.
4) Stir the cream mixture slowly into the eggs and sugar a little at a time, until about 1/3 of the cream mixture has been added. Pour in the remainder and return the entire mixture to the saucepan. Place over a low heat. Continue to cook, stirring frequently, until the mixture thickens enough to coat the back of a spoon. Pour the mixture into a container and leave at room temperature for 30 minutes.
5) Stir in the vanilla extract. Place the mixture into the refrigerator. When it is cool enough not to form condensation on the lid, cover and store for 4 to 8 hours or until the temperature reaches 40 degrees F or below.
6) Pour into an ice cream maker and freeze according to the manufacturer's directions. This should take approximately 25 to 35 minutes for soft scoop, or freeze for another 3 to 4 hours to harden fully.