Cacao butter is the oil content of the Cacao bean, extracted when the beans are pressed, separating the butter from the Cacao paste. There are lots of Cacao Butters on the market. One thing to consider is that it is quite high in saturated fat.
Sevenhills Cacao Butter is my favourite.

Macros

Macronutrient Per 100g
Fat 99.5g
- Of which saturates 60.6g
Protein 0.2g
Carbohydrate 0.1g
- Of which sugar 0.1g