Cut oranges across the middle, section out pulp, until you have 4 1/2 cups
Pulse in a blender, or in a medium-sized pot with an immersion blender
Stir in lemon juice, sugar and sure gel
Add in cinnamon stick, and heat pot over medium heat
While mixture heats, place a small plate in the freezer
Bring to a boil, and boil about 25 minutes, until mixture passes the “jam test”
To test jam, drop a small spoonful on frozen plate to see how thick jam is when it cools. Continue testing until jam is thickened to your preference
To can: Ladle jam into sterilized canning jars. I usually use 4oz. or 8 oz. jars.
Place in a waterbath canner of hot water, making sure canning rack is inserted into bottom of canner
Make sure water level reaches at least one inch above the top of your jars
Cover canner and bring to a rolling boil for 8 minutes for 4oz. jars, 8 minutes, 8 oz. jars for 10 minutes, and 16 oz. jars for 15 minutes
When canner is done boiling, remove from heat and let cool at least 15 minutes before removing lid, and letting cool for another 15 minutes before removing jars.
When removing hot jars from canner, be sure to protect them from drafts to prevent glass breaking. One way to do this is to cover them with a towel as they cool
Store sealed jars in a cool place out of direct light.