Prepare a baking sheet and line with parchment paper, if desired. Add sugar, salt, and water to a large nonstick frying pan and warm up on high heat while constantly stirring until sugar is dissolved. Add cinnamon and stir to combine.
Add almonds to the pan and toss to coat with syrup. As soon as all the water is evaporated, turn down the heat to medium and keep stirring. The coating should turn matte and dull a bit. Keep stirring while the almonds start to caramelize and get shiny again. Continue to stir to avoid any burning.