Thread each hazelnut onto the tip of a long wooden skewer or toothpick, and set aside.
Place a cutting board or marble board along the edge of a countertop, and set a baking sheet covered with waxed paper on floor next to edge of that countertop to catch the drips of candy from the hazelnuts.
Cook the sugar and water in a heavy bottomed medium saucepan over medium heat, stirring occasionally, until the sugar dissolves.
Continue to cook the sugar, without stirring, until the syrup comes to a boil. Wash the sides of the pan down with a wet brush to prevent crystals from forming. Let the syrup boil until it turns light brown in color, about 5 minutes; remove from heat. Let the syrup sit until slightly cooled, about 8 to 10 minutes.
Dip one of the skewered hazelnuts into the cooled syrup, coating the hazelnut completely, and letting the excess syrup drip back into the pan. When the dripping syrup becomes a thin string, secure end of the skewer under the cutting board, let the caramelized sugar string drip over edge and onto the baking sheet that’s on the floor.
Repeat with remaining hazelnuts. Let the candied hazelnuts stand until the syrup has hardened, at least 5 minutes. Carefully remove skewers from under the cutting board, and garnish your dessert with the skewered candied hazelnuts.