Place the cherries, sugar, orange juice and pectin into a deep sided saucepan over a medium heat.
Cook over a medium heat, stirring occasionally until the sugar has melted.
Add a cinnamon stick, if using.
Continue cooking over a medium heat, increasing the heat slightly so that the mixture comes to a boil. Allow this to boil until it begins to thicken and reaches 220°F (105C) on a food thermometer.
Remove from the heat and decant into a baking tray to cool quickly or into a heatproof storage bowl.