Wash the nespra seeds and place them on a tray.
Leave them to air dry for 48 hours.
Take a large, sterilised jar and add the seeds.
Add the cinnamon stick.
Peel the outer skin from the lemon and add it to the seeds.
Quarter the lemon and add it to the jar.
Top with the vodka and stir.
Seal the lid closed and place the jar on a windowsill for a month.
During the month, shake the jar.
After the month, pass the contents of the jar though a sheet of muslin.
Discard the seeds etc and retain the liquid.
Boil the water and sugar and make a syrup.
Boil the liquid for 8 minutes or so. Allow the syrup to cool.
Combine the syrup and base liquid together.
Pour the liquor into sterilised bottles and enjoy.