Heat water in a saucepan over medium heat and boil the lemon in it for about 2 minutes.
Allow it to cool down and then pat dry. Use a sharp knife to thinly slice the lemon, making sure you remove the seeds.
Stack the lemon slices in a clean glass jar with a sprinkle of cinnamon between them. Pour the honey over the top.
Refrigerate for 4-6 days to allow the natural juices from the lemon to release into the honey.
Notes
Allowing the honey to rest for a few days before you use it is important. This helps the flavors of the lemon infuse into the honey.
If you don't have the time to allow the honey to rest and want to whip this up quickly, warm up the honey slightly in a saucepan and then add the lemon slices into it. Let this cook for a couple of minutes, remove from heat and let it refrigerate for a few hours before you serve.
If you're using ground cinnamon, remember that less is more. Don't add too much, as it can make the honey taste bitter.
You can also add herbs like thyme and rosemary or even some turmeric powder if you want to. I actually made an incredible turmeric ginger honey that turned out to be SO useful during the flu season.
Refrigeration will cause the honey to crystallize and that's normal. If you notice it, simply get it out and place it in a water bath to warm it up slightly.