Cool the cake in the cake pan for approximately 20 minutes before removing from the pan. Serve warm or at room temperature with cacoa powder sifted on top.
If you don't have cacao butter, or can't find it at your local grocer or health food store, exchange it for coconut oil in equal measure. I prefer the taste of cacao butter in the recipe which helps give it a more authentically chocolate taste and rich texture. The coconut oil variation is just as lovely though; I've made and eaten it both ways.