Put the apple juice, the rest of the berries, 4 orange slices, cinnamon powder and star anise in a large saucepan and bring to the boil over a moderately high heat, stirring occasionally.
Reduce the hotplate temperature. Simmer the mixture until the blackberries begin to let color. Strain the mixture through a sieve and dispose of the residue.
Pour the hot liquid into 6 heat-resistant glasses. Halve the remaining 3 orange slices and garnish each glass with half an orange slice, a blackberry and a piece of cinnamon stick.