How to Make It
Preheat oven to 350°F. Spread hazelnuts in a single layer on a rimmed baking sheet, and toast in preheated oven until golden and blistered, 10 to 15 minutes, stirring halfway through toasting. Remove from oven, and immediately wrap toasted nuts in a dish towel. Let stand 1 minute. Rub hazelnuts in the towel to remove skins. Let cool slightly, about 10 minutes. Discard skins.
Combine hazelnuts, sugar, and salt in a high-speed blender. Pulse until nuts are finely chopped. Process on high speed until nut butter is smooth, 3 to 5 minutes, scraping down sides of blender carafe as needed.