Add the water with the sugar and cinnamonto a tall, non-stick pan and bring everything to a boil, mixed together, over medium-low heat.
Now add the unpeeled almonds and stir well. The mixture will simmer away and thicken more and more. You must always stir well, no lumps should form and nothing should burn.
When the water has evaporated, the sugar looks crumbly. Now you must act quickly. Put the stove on high heat briefly until the sugar starts to liquefy and then back down to medium heat.
Keep stirring diligently until the sugar begins to caramelize. It becomes brown-liquid and now settles around the almonds. Now it is important to stir well so that all the almonds are well coated in the sugar but nothing burns. This should take about 8-10 minutes.
Now turn off the heat and take the pan off the heat. Stir the last bits together well and pour everything onto a baking sheet lined with parchment paper to cool.