Cut the dates in half, and remove the stone. Put them in a saucepan and cover with 2 cups of water. Bring the water to hard boil; reduce the heat to a simmer and simmer for 15 minutes.
Drain the dates, reserving ½ cup of the cooking liquid.
Transfer the dates to a blender and add the cooking liquid, lemon juice, maple syrup and cinnamon. Blend until a smooth paste forms.
Transfer to a jam jar and store in the fridge.
