Roast the hazelnuts until they are just starting to colour, and you can smell their warm aroma.
Remove from oven and turn off.
Place hazelnuts in the Thermomix bowl on reverse speed 1 for about a minute. The skins should come off pretty easily. (If you don't have a Thermomix, or you need to remove more skin, agitate the nuts between two dishclothes.
Separate the skins
Place the hazelnuts back in the bowl and whiz for 5 seconds on speed 4. You want them broken up, but NOT powdered or turned to flour. Without a Thermomix, you can do this with a rolling pin.
Place the Rapadura and water in the bowl/a large pot and bring to the boil. Add the hazelnuts and leave to boil until the mixture has reduced by about 25%
You will need to stir it regularly to make sure it doesn't burn. If you're using a Thermomix, just keep it on speed 1.
Once it's reduced, strain to remove the nuts, and put them aside for crystallised hazelnuts. Strain again to remove smaller nuts, and pour into the container you'll be keeping it in. Leave to cool before refrigerating.
If you taste it straight away you'll be disappointed by how mild it tastes. Leave for about 24 hours before having your first sip of real hazelnut syrup. You won't be disappointed.
Recipe by Keeper of the Kitchen at https://www.keeperofthekitchen.com/2013/05/04/home-made-hazelnut-syrup/