Pre-heat oven to 350 degrees. On a sheet pan, place raw hazelnuts. Roast until browned and fragrant- about 8-10 minutes. Place warm hazelnuts in a clean dry dish towels and rub vigorously until the skins peel off. Set aside.
In a heavy bottomed saucepan, bring water to a simmer, add in sugar and salt. take care to remove any sugar from the sides of the pan with a pastry brush. Bring to a boil until sugar is dissolved- about 2 minutes. With a slotted spoon, gently add in hazelnuts and stir to coat. Remove from heat. Using the same slotted spoon, place the hazelnuts on a rimmed sheet pan lined with parchment paper (I just use the pan for easy cleanup). Roast in an oven for 5-6 minutes until golden brown. Remove the pan from the oven and let the nuts cool completely. Place in an airtight container until ready to serve.