1. Prick the sweetpotatoes with a fork all around and bake at 220 °C top and bottom heat for 20-40 minutes, depending on size/thickness, until the flesh is very soft. Leave to cool.
2. Scrape the flesh out of the shell with a spoon and place in a tall container.
3. Add the cocoa powder and salt and purée everything together very finely.
4. Serve in small bowls garnished with berries, mint and cocoa powder.