1. Melt butter and chocolate over a water bath and stir it together until it forms a homogeneous mixture. Remove the bowl from the heat.
2. Stir the cream into the chocolate until it begins to thicken.
3. Once the cream and chocolate are well combined, pour the chocolate over the cake and smooth it out to an even layer.
4. Place the cake in the fridge for at least 30 minutes or until the chocolate has set.
The cake is ready to serve
