Method

Melt the chocolate and butter together over a low heat in a saucepan. Remove from the heat and allow to cool slightly before adding the vanilla extract.

In another bowl beat the eggs, cream and sweetener together for 3-4 minutes (use a stick blender or hand whisk). It will go frothy and remain runny.

Slowly add the egg mixture to the chocolate mixture in the saucepan, stirring all the time. As you add more egg mixture, the chocolate and butter will thicken to the consistency of custard.

Pour into a prepared tin (see below). Grease a loose bottom cake tin with butter then line the loose bottom with baking paper and push through the outer ring so the baking paper adds a seal and stops the cake mixture from leaking.

Bake at 180C for 20 - 30 minutes, or more depending on your oven. Bake until it is just set in the centre, do not overcook the cake.