Directions

1. Preheat oven to 350º F. Spread hazelnuts out on a sheet pan. Toast them. Agitate the sheet pan a few times to make sure they’re browning evenly. You want them to get a shade darker, but not to burn -- this takes about 10 minutes. Cool for a few minutes.
2. Place hazelnuts on a large dishtowel. Pull the four corners together and twist closed like a little package (looks like a beggar’s purse). Keeping the towel tightly closed, roll the nuts around on the counter with your hand to loosen their skins. Occasionally open it up to check -- you want to rub the hazelnuts together until about half of the skins come off.
3. Open dishtowel. Pick out the nuts, leaving the skins behind. By hand or in the food processor, chop the hazelnuts. I like some bigger chunks in my brittle, but the size is up to you.
4. You will need to move quickly once the sugar caramelizes, so get ready by covering a sheet pan with parchment paper. Find a spreading tool like a large offset spatula or a wooden spoon. Set aside.
5. Place sugar in a medium-sized saucepan. Add just enough water to soak the sugar. Swirl (by the pot handle) until all the sugar is wet. Place over medium heat. It will boil. The sugar will dissolve. Don’t stir. Don't walk away. Swirl around (by the pot handle) if it's not caramelizing evenly. Cook until it's almost at desired color (Grade B maple syrup or darker). Turn off the heat and stir in the chopped hazelnuts. Stir in vanilla and salt. Immediately pour onto parchment paper on prepared sheet pan. It hardens very quickly so spread it out as fast as you can until it’s about 1/2 inch thick. Be careful. As I say to my kids: this sugar is so hot it could kill you.
6. It will cool and firm up within fifteen minutes. Break into chunks. Melt chocolate over low heat. One at a time, dip half of each piece of brittle into the chocolate and place back down on parchment on the sheet pan. Place sheet pan in fridge or freezer to firm up the chocolate. A speedier (and fun) option is to just drizzle the chocolate all over the brittle. Store in an airtight container for a few weeks. Or freeze.