Wash the oranges well and pat them dry. Cut the oranges into quarters lengthwise, then remove the pips and the cut off the central whitish core. Then chop the quarters into halves and blend till chunky. Put all the pips in small piece of cotton cloth and tie it into a pouch.

Keep a plate in the freezer to chill, before staring the jam. Put the blended oranges, sugar, orange juice and ginger in a heavy pot. Mix well, and bring to a boil. Add the whole cinnamon (if using powdered cinnamon add it later) and the pouch of the orange pips to the pot. Turn down the heat to medium and let it simmer until it starts thickening. Keep stirring frequently to ensure the jam doesn’t stick to the pan and burn. When the jam has thickened enough and seems almost ready, stir in the powdered cinnamon if you’re using it instead of whole.

Once the jam seems ready, take the plate out of the refrigerator. Drop a little jam on the cold plate. Push it a little from the edge with your finger. If it wrinkles, the jam is done.

Stir in the butter and then take the jam off the heat. Remove the pouch of pips and discard. Let the jam cool a bit. Then transfer it to sterile glass jars while still hot. Cover with airtight lids.