Wash the orange, rub dry and finely grate the peel. Sort the blackberries. Wash and drain. Puree the blackberries finely and put them in a pot with honey and orange juice. Heat while stirring and boil down for about 3 minutes until thick. Remove from the heat and let it cool down.
Stir the blackberry mixture with orange peel and cinnamon into the butter. Pour blackberry butter into 2 clean, hot rinsed glasses (210 ml each) and close them. Blackberry butter can be kept in the refrigerator for about 10 days.