Wash rhubarb and cut in slices
Place rhubarb slices in a big pot and add water, bring to a boil and let it simmer on medium-low heat until rhubarb have softened (should take max 10 min)
Take a hand mixer and make a smooth rhubarb mixture (if you prefer the jam with pieces then you can skip this step)
Pour in the sugar while stirring, keep stirring until it has dissolved
Add cinnamon to your liking, stir and let it boil until you get the thickness you want. 15 minutes is what we usually end up with
Sterilize cans and then fill them up with the jam. Let it cool and enjoy your 3 cans of homemade delicious rhubarb jam with cinnamon!