Heat the oven to 180°C. Grease and base line a 22cm round cake tin.
Melt the chocolate with the butter in a heatproof bowl over a pan of simmering water. Remove from the heat and cool to room temperature.
Beat the eggs and sugar in a mixing bowl until soft and creamy. Sift in the flour , potato starch, and baking together, mixing well until well blended. Add the melted chocolate with butter and orange rind, and give a final mix.
Transfer the mixture to the prepared cake tin and bake for 45 minutes or until a skewer comes out clean when inserted into the center. Remove from the oven and leave to cool.
Put water and sugar in a large frying pan. Let it boil. Arrange orange slices in the pan. Continue boiling until all the slices are golden brown with sugar. Put orange slices in a baking paper to dry. Set aside the remaining caramel syrup.
Remove the cake from the tin and place on a serving cake dish. Decorate with orange slices and remaining caramel syrup.
Serve, share and enjoy!
